Below, we show that DNA damage in the form of O6-methylguanosine is specifically associated with the ability of cycasin/MAM to disrupt murine neurodevelopment (Kisby et al., 1999, 2009) and that failure to repair this type of DNA lesion by O6-methylguanine methyltransferase (MGMT) activates cellular pathways in the rodent brain that are associated with both cancer and human neurodegenerative disease (Kisby et al., 2011a). The gene discussed is MGMT; the disease is cancer.