PHF11 (PHD finger protein 11) is a nuclear transcriptional co-activator with pleiotropic functions in immunity and DNA repair. As a positive regulator of Th1-type cytokine gene expression, PHF11 cooperates with NF-κB to enhance transcription of interferon-γ (IFNG) and interleukin-2 (IL2) 1. Beyond cytokine regulation, PHF11 contributes broadly to T-cell activation and viability through multiple mechanisms: it shuttles between cytoplasm and nucleus upon T-cell activation, recruits NF-κB to the IFNG promoter, and regulates expression of genes required for T-cell differentiation and homeostasis 1. Additionally, PHF11 functions as a DNA damage response factor that promotes double-strand break resection, ATR signaling, and homologous recombination repair by stimulating the EXO1 exonuclease and overcoming RPA-mediated inhibition 2. PHF11 polymorphisms are associated with allergic diseases including asthma and eczema in multiple populations 3, 4, though this association shows population-dependent variation 5. Notably, PHF11 also exhibits antiviral activity by selectively inhibiting foamy virus basal transcription from the internal promoter, preventing viral transactivator expression and promoting viral latency 6. In cancer contexts, PHF11 has been identified as a prognostic biomarker for melanoma survival prediction when combined with immune checkpoint markers 7.