Based on limited published evidence, TRIM64 is an E3 ubiquitin protein ligase localized to the cytoplasm with annotated functions in innate immune response and gene expression regulation. A single study identified TRIM64 mRNA as upregulated in peripheral blood mononuclear cells of hepatocellular carcinoma patients responding to atezolizumab-bevacizumab immunotherapy versus nonresponders at 3 weeks post-treatment initiation, suggesting potential involvement in immune activation 1. Specific molecular mechanisms and cellular targets remain largely undetermined.