For example, Smurf1 boosts cell invasion by degrading tumor suppressors [e.g., Ras homolog gene family member A (RhoA), hPEM-2, DAB2 interacting protein (DAB2IP), Kindlin-2] and altering cellular localization of substrates [e.g., tumor necrosis factor receptor-associated factor 4 (TRAF4)] (14–18), and it inhibits p53/DNA damage-mediated apoptosis by degrading corresponding factors (e.g., ING2, RhoB, KLF2) and stabilizing MDM2 (19–22). Here, TRAF4 is linked to neoplasm.