BATF2 is an AP-1 family transcription factor that functions as a tumor suppressor with critical roles in immune regulation and cancer control. As a basic leucine zipper transcription factor, BATF2 forms heterodimers with JUN family proteins to regulate target gene expression by binding DNA sequences 5'-TGA[CG]TCA-3' 1. In gastric cancer, BATF2 acts as a tumor suppressor by inhibiting cancer stem cell properties and chemoresistance through the PTEN/AKT/β-catenin signaling pathway, enhancing 5-fluorouracil sensitivity 2. BATF2 regulates T-cell exhaustion by controlling RGS2 expression; BATF2 deficiency increases CD8+ effector T cells and reduces exhaustion markers in lung cancer models 3. The transcription factor promotes type-I interferon-dependent anti-tumor immunity, with glutamine metabolically suppressing its expression in head and neck cancers 1. BATF2 expression predicts favorable responses to anti-PD-1 immunotherapy in gastric cancer and serves as a biomarker component for immune activation status 4, 5, 6. Additionally, BATF2 expression differentiates active tuberculosis from other respiratory diseases 7. In colorectal cancer, BATF2 downregulation by PD-1 signaling suggests context-dependent roles in immune checkpoint biology 8. Together, these findings establish BATF2 as a metabolically-regulated tumor suppressor essential for anti-tumor immunity and chemotherapy responsiveness.