The following paper is forthcoming in the journal Biosystems A new theory of the origin of cancer: Quantum coherent entanglement, centrioles, mitosis and differentiation Stuart R. Hameroff M.D. Professor Emeritus, Departments of Anesthesiology and Psychology Associate Director, Center for Consciousness Studies The University of Arizona, Tucson, Arizona www.consciousness.arizona.edu/hameroff hameroff@u.arizona.edu Abstract: Malignant cells are characterized by abnormal segregation of chromosomes during mitosis (“aneuploidy”), generally considered a result of malignancy originating in genetic mutations. However recent evidence supports a century-old concept that maldistribution of chromosomes (and resultant genomic instability) due to abnormalities in mitosis itself is the primary cause of malignancy rather than a mere byproduct. In normal mitosis chromosomes replicate into sister chromatids which are then precisely separated and transported into mirror-like sets by structural protein assemblies called mitotic spindles and centrioles, both composed of microtubules. The elegant yet poorly understood ballet- like movements and geometric organization occurring in mitosis have suggested guidance by some type of organizing field, however neither electromagnetic nor chemical gradient fields have been demonstrated or shown to be sufficient. It is proposed here that normal mirror-like mitosis is organized by quantum coherence and quantum entanglement among microtubule-based centrioles and mitotic spindles which ensure precise, complementary duplication of daughter cell genomes and recognition of daughter cell boundaries. Evidence and theory supporting organized quantum states in cytoplasm/nucleoplasm (and quantum optical properties of centrioles in particular) at physiological temperature are presented. Impairment of quantum coherence and/or entanglement among microtubule- based mitotic spindles and centrioles can result in abnormal distribution of chromosomes, abnormal differentiation and uncontrolled growth, and account for all aspects of malignancy. New approaches to cancer therapy and stem cell production are suggested via non-thermal laser mediated effects aimed at quantum optical states of centrioles. Key words: Cancer, centrioles, differentiation, genomic instability, malignancy, microtubules, mitosis, mitotic spindles, neoplasm, quantum coherence, quantum computation, quantum entanglement, quantum theory, stem cells Theories of the origin of cancer: mutation, aneuploidy, genomic instability Malignant cells divide and multiply uncontrollably. They evade built-in autodestruct mechanisms, stimulate formation of blood vessels to feed themselves, and can invade other tissues. Proper differentiation – the process by which genetic expression leads to