Intronic variants of the gene encoding PDIA1 were reported to be a genetic risk factor for sALS and fALS (Kwok et al., 2013; Yang and Guo, 2016) and nine PDIA1 missense variants and seven PDIA3 missense variants were documented in 16 ALS patients (Gonzalez-Perez et al., 2015). The gene discussed is P4HB; the disease is amyotrophic lateral sclerosis.