SQSTM1 and amyotrophic lateral sclerosis: Furthermore, a number of familial ALS-associated proteins are known to be involved in protein quality control mechanisms, including C9orf72, valosin-containing protein (VCP), sequestosome-1/p62, ubiquilin-2, optineurin, dynactin, and TBK1 (reviewed in Webster et al., 2016b).