Master California Supreme Court rejected a conversion claim over excised human cells but allowed claims for breach of fiduciary duty and lack of informed consent based on undisclosed financial interests. with this comprehensive case brief.
Moore v. Regents is a landmark California Supreme Court decision at the intersection of property law, torts, and bioethics. It addresses whether a patient retains a property interest in tissues and cells removed from his body—enough to sue hospitals and researchers in conversion when those materials are used for profitable research. The court’s answer—no conversion claim—has profoundly shaped the legal framework governing biotechnology, tissue banking, and biomedical research, while simultaneously reinforcing physicians’ duties to disclose personal financial interests that could skew medical judgment.
For law students, Moore is essential because it illustrates how courts balance individual autonomy and property-based claims against societal interests in scientific progress. The opinion delineates the limits of property rights in human biological materials, clarifies that informed consent and fiduciary duty (not conversion) are the appropriate vehicles for redressing undisclosed conflicts, and surfaces competing judicial philosophies about commodification of the human body, as reflected in the concurring and dissenting opinions.
Moore v. Regents of the University of California, 51 Cal. 3d 120, 271 Cal. Rptr. 146, 793 P.2d 479 (Cal. 1990)
John Moore was treated at UCLA Medical Center for hairy-cell leukemia by Dr. David Golde. In October 1976, Moore’s spleen was surgically removed as part of his treatment. Without disclosing their research and commercial intentions, Dr. Golde and the Regents of the University of California retained and used Moore’s blood, bone marrow, and other biological materials over many follow-up visits to develop a unique cell line with valuable properties. The Regents obtained a patent on the “Mo” cell line (naming Moore in part as the source of the cells) and entered into lucrative agreements with private companies; Dr. Golde personally received compensation and stock interests. Moore alleged he was never informed of the research’s commercial potential or of Dr. Golde’s financial interests; he signed standard consent forms permitting procedures and generic research use but not specific disclosures of conflicts. Moore sued for, among other claims, conversion of his excised cells and their products, breach of fiduciary duty, and lack of informed consent. The trial court dismissed the conversion claim; the court of appeal reinstated it; the California Supreme Court granted review.
Does a patient retain a property interest in excised cells that supports a tort claim for conversion when those cells are used for commercial research, and did the physician breach duties by failing to disclose personal research and financial interests that could influence medical judgment?
Conversion requires the plaintiff’s ownership or right to possession in the personal property at issue. Under California law, a patient does not retain a property interest in excised cells sufficient to sustain conversion, particularly given statutory and policy considerations governing human tissues and the public interest in biomedical research. Separately, a physician owes fiduciary duties and must obtain informed consent, which includes disclosing personal interests unrelated to the patient’s health that may affect professional judgment; nondisclosure of such conflicts can constitute breach of fiduciary duty and lack of informed consent.
The court held that Moore had no property interest in his excised cells to support a conversion claim; thus, the conversion cause of action failed. However, Moore adequately stated causes of action for breach of fiduciary duty and lack of informed consent based on Dr. Golde’s failure to disclose research and financial interests; those claims could proceed.
The majority rejected Moore’s conversion theory for three principal reasons. First, the court found no traditional or statutory basis recognizing continuing ownership in cells once removed from the body. California’s health and safety statutes—including regimes governing the disposition of human tissues and the Uniform Anatomical Gift Act—contemplate regulated use, donation, and disposal of human biological materials, not retention of possessory interests by patients after excision. Recognizing a property right sufficient for conversion would conflict with these frameworks and create uncertainty about lawful possession after removal. Second, policy considerations militated against imposing conversion liability. Conversion is a strict liability tort; extending it to human tissues would expose innocent downstream researchers and institutions—often far removed from any alleged wrongdoing—to substantial liability, chilling beneficial biomedical research. The court emphasized the difficulty of tracing individual proprietary claims in widely distributed samples and cell lines, and the impracticality of requiring researchers to investigate title to every sample. Third, the court reasoned that the patented cell line and its products were factually and legally distinct from Moore’s raw cells. Although Moore’s biological materials were the source, the inventive labor and scientific transformation created a new product with attributes not naturally occurring in Moore’s body. The patent’s novelty requirement underscored this distinction, weakening claims that Moore owned the resultant cell line or its derivatives. At the same time, the court underscored robust duties of disclosure. Physicians must disclose personal research and economic interests that are unrelated to the patient’s health but could affect medical judgment. Moore alleged that Dr. Golde orchestrated follow-up visits primarily to harvest materials for research and profit, without disclosing his financial stake. Such nondisclosure can vitiate informed consent and breach fiduciary obligations, allowing recovery under those tort theories. These remedies, the court reasoned, appropriately target the relational wrong (lack of informed disclosure) without converting human tissues into property for purposes of strict liability. Concurring opinions stressed moral concerns about commodifying the human body, while a partial dissent (Justice Mosk) favored recognizing a limited property interest to deter exploitation and allow compensation. The majority acknowledged these competing concerns but concluded that doctrinal fit and policy favored informed-consent and fiduciary-duty remedies over a broad conversion right.
Moore is foundational for understanding how courts cabin property claims in human biological materials while emphasizing fiduciary and informed-consent doctrines to police conflicts of interest. It shapes institutional practices in biobanking and research, encourages transparent conflict disclosures by clinicians-scientists, and influences debates over commodification and patient participation in the value derived from their tissues. For law students, the case is a crucial study in the tension between individual rights, doctrinal coherence in property/torts, and innovation policy in biotechnology.
Yes. Moore signed standard consent forms authorizing medical procedures and generic research use. However, the court held that informed consent requires disclosure of material information, including a physician’s personal financial or research interests that could affect medical judgment. Generic research language did not excuse the failure to disclose Dr. Golde’s specific conflicts, so Moore’s fiduciary duty and informed consent claims could proceed.
Moore holds that, under California law, a patient lacks a property interest in excised cells sufficient to support a conversion claim. It does not create a categorical rule about all possible property interests in all contexts, nor does it bar contractual arrangements or statutory regimes that might grant specific rights. But as a practical matter, Moore is widely cited to reject conversion-based ownership claims over tissues once removed.
The court permitted claims for breach of fiduciary duty and lack of informed consent to proceed. Remedies for those claims focus on harms caused by nondisclosure, not on the market value of the cell line. The Supreme Court did not set damages; it remanded for further proceedings, leaving available remedies to be determined under standard tort and fiduciary principles.
Conversion imposes strict liability for interference with property. If excised tissues were property of the patient, anyone who later used those materials—even downstream researchers unaware of any problem—could face liability. The court feared this would chill scientific research by creating transactional uncertainty and high litigation risk, especially given the widespread sharing of biological materials.
The patent underscored that the cell line was a product of inventive effort and materially different from Moore’s unmodified cells. While the patent did not determine ownership of the source materials, it supported the court’s view that the cell line is legally distinct, weakening Moore’s claim that he owned the cell line or its proceeds through a property theory.
Physician-researchers must disclose personal financial and research interests that could influence clinical decisions. Even if research use is generally permitted by consent forms or institutional policies, undisclosed conflicts can breach fiduciary duties and invalidate informed consent, exposing physicians and institutions to liability.
Moore v. Regents draws a bright line against recognizing conversion claims in excised human tissues, prioritizing legal coherence and innovation policy over an expansive property-rights approach to the body. In doing so, it channels patient protection into fiduciary duty and informed-consent doctrines, emphasizing transparency about physician conflicts and respect for patient autonomy in decision-making.
For students and practitioners, Moore is a touchstone for analyzing disputes involving human biological materials. It illustrates how courts reconcile competing values—individual rights, the ethics of commodification, and the needs of scientific progress—by selecting doctrinal tools that mitigate abuse (disclosure-based duties) without imposing strict liability regimes that could stall biomedical research.