TRIM21 and infection: Tripartite motif (TRIM) protein family members (numbering >70) have been implicated in various cellular functions, including cell proliferation, differentiation, development, apoptosis, antiviral activity, autophagy and oncogenesis.44 TRIM21 plays a pivotal role in immune activation during pathogen infection, but its cellular function remains unclear.45 Interestingly, CSN6 is able to decrease the steady-state expression of TRIM21 by enhancing TRIM21 ubiquitination, thereby promoting cancer stemness.