ETV4 (ETS variant transcription factor 4) is a transcriptional activator that plays critical roles in cancer progression and cellular differentiation 1. As a DNA-binding transcription factor, ETV4 recognizes specific ETS-binding sequences and activates target gene transcription, including key oncogenes and inflammatory mediators 2. In hepatocellular carcinoma, ETV4 promotes metastasis by transactivating PD-L1 and CCL2 expression, leading to immunosuppressive tumor microenvironments and increased macrophage infiltration 1. ETV4 also drives hepatic inflammation and carcinogenesis by directly activating TNF-α and MAPK11 transcription 2. In bladder cancer, ETV4 facilitates lymphangiogenesis and lymph node metastasis through CXCL1/8-mediated neutrophil recruitment, with its nuclear translocation enhanced by PTK6-mediated phosphorylation at tyrosine 392 3. The protein functions as an intermediate state regulator in melanoma phenotype switching, contributing to a distinct gene regulatory network 4. ETV4 expression is regulated through multiple mechanisms, including FGF19/FGFR4 signaling via ERK1/2 pathway 1, and m6A-mediated mRNA stabilization in cholestatic liver fibrosis, where it paradoxically promotes anti-fibrotic responses through MMP9 induction 5. ETV4 overexpression characterizes CIC-rearranged sarcomas, serving as a diagnostic biomarker 67.