PDC and amyotrophic lateral sclerosis: The association of ALS-PDC with cycad exposure, and in particular with the genotoxin, carcinogen, and neurotoxin MAM, has for decades led to the suspicion that cancer and neurodegenerative diseases may be related disorders (Whiting, 1988), mechanistic evidence for which was presented recently and is discussed later in this paper (Kisby and Spencer, 2011; Kisby et al., 2011a).