CCS and amyotrophic lateral sclerosis: Notably, CCNF and CCS, both known ALS genes, were identified as significantly downregulated in the ALS twin compared to their unaffected co-twin (CCNF: logFC = 0.70, t = 3.99, FDR = 0.027; CCS: logFC = 0.70, t = 6.42, FDR = 0.008, Fig. 6B).