CDKN2A and nasopharyngeal carcinoma: Ubiquitination and degradation of PHB1 leads to transcriptional activation of NF-κB and STAT3.189 TRIM21 mediates small G-protein signaling modulator 1 (SGSM1) ubiquitination degradation and inhibits the MAPK pathway activation.190 Deubiquinase ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) from the UCH family forms complexes with p53/MDM2/ARF and deubiquitinates p53 promoting p53 signaling, which is involved in NPC pathogenesis.191