Guam ALS/PDC neurons with tau inclusions contain mitotic markers (Husseman et al., 2000; Stone et al., 2011) indicative of abnormal neuronal development, as occurs in neonatal rodents treated with cycasin or MAM (Sullivan-Jones et al., 1994; Ferguson, 1996; Kisby et al., 2013). The gene discussed is MAPT; the disease is amyotrophic lateral sclerosis.