TRAF6 and neurodegenerative disease: Instead of conventional K63-linked polyubiquitination, TRAF6 promotes atypical ubiquitination of DJ-1, aSYN and N-HTT with K6, K27, and K29 linkage formation, thereby stimulating aggregate formation of mutant DJ-1, aSYN and N-HTT in neurodegenerative diseases [326,327].