CTSS and amyotrophic lateral sclerosis: Importantly, the A-allele of rs4970944 (linked to a later ALS onset) is significantly associated with reduced expression of CTSS in cerebellum (P = 0.00018, NES = −0.31, n = 209; Additional file 1: Fig. S9), with similar results for its tagging SNPs (P = 0.00018, NES = −0.31 for rs10888406; P = 0.000056, NES = −0.34 for rs11204785; P = 0.000059, NES = −0.33 for rs11807075).