MAPK8 and cardiac hypertrophy: Deleting or mutating (C70A mutant) TRAF6 ring domain (with ubiquitin ligase activity) inhibits both K63 ubiquitination of TAK1 and activation of p38 and JNK signaling, demonstrating the importance of TRAF6 E3 ligase activity in inducing pathologic cardiac hypertrophy (Cao et al., 2015; Ji et al., 2016).