POU2AF1 is a transcriptional coactivator that associates with POU2F1/OCT1 and POU2F2/OCT2 transcription factors to enhance their promoter activity by recognizing their POU domains 12. In B cells, POU2AF1 is essential for antigen response and germinal center formation 31. The protein functions as part of a regulatory complex with POU2F proteins across multiple cell types: in tuft cells, POU2AF1 paralogues (OCA-T1/POU2AF2 and OCA-T2/POU2AF3) associate with POU2F3 as master regulators of tuft cell identity and tuft-cell-like small cell lung cancer 4. In mesenchymal stem cells, POU2AF1 promotes adipogenesis by inhibiting HDAC1 expression 5. POU2AF1 is implicated in disease pathogenesis: it is upregulated in hepatocellular carcinoma and identified as a potential therapeutic target 6, functions as a hub gene in rheumatoid arthritis synovial tissue involved in IL-6/JAK/STAT3 signaling 7, and is downregulated in established RA patients 8. Additionally, POU2AF1 serves as a candidate biomarker for radiation exposure, showing linear dose-response relationships in human blood samples 9. B cell malignancies dependent on POU2AF1 demonstrate vulnerability to mSWI/SNF complex inhibition, providing a therapeutic avenue 10.