PRPH and amyotrophic lateral sclerosis: Fourteen out of 126 genes associated with ALS (mostly by mutation or GWAS studies) from the specialized ALSoD database14 showed differential expression in our ALS samples, 10 were down-regulated (including PRPH, UNC13A, SLC1A2, SNCG and NEFH) and 4 were up-regulated (SOD2, APOE, LOX and RNASE2).