AUTHOR=Li Aizhuo , Wang Jiannan , Qu Yi TITLE=TRIM21: a multifaceted regulator in cancer JOURNAL=Frontiers in Cell and Developmental Biology VOLUME=Volume 13 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2025.1637451 DOI=10.3389/fcell.2025.1637451 ISSN=2296-634X ABSTRACT=Ubiquitination serves as a dynamic post-translational modification that enables rapid and precise regulation of cellular signaling networks. TRIM21, as an important member of the TRIM family, is a protein with E3 ubiquitin ligase activity. By specifically recognizing and ubiquitinating various substrate proteins, it plays a pivotal regulatory role in tumorigenesis and development. Moreover, TRIM21 has been found to play a multi-faceted role in cellular autophagy, metabolic reprogramming, immune escape, tumor proliferation, metastasis and resistance to cell death by regulating the stability and function of key proteins. In this review, we provided an in-depth understanding of the specific mechanism of TRIM21 in different biological processes and tumor types, which contributes to the development of novel targeted therapeutic strategies targeting TRIM21.