BANF1 (Barrier to Autointegration Factor 1) is a nuclear envelope protein that plays critical roles in chr11 organization, genome stability, and immune regulation. The protein functions as a homodimer that binds non-specifically to DNA, compacting chr11 through a looping process 1. BANF1 is essential for maintaining nuclear envelope integrity and proper chr11 structure, with loss of function resulting in aberrant nuclear morphology 1. In embryonic stem cells, BANF1 is required for self-renewal and survival, associating with the master regulator Sox2 2. The protein also serves as a natural inhibitor of the cGAS-STING innate immune pathway by preventing cGAS activation on genomic DNA 3. Disease-wise, mutations in BANF1 cause Néstor-Guillermo Progeria Syndrome, a severe premature aging disorder 41. Additionally, BANF1 is upregulated in various cancers including esophageal and colorectal cancer, where it promotes tumor progression and correlates with poor prognosis 563. Therapeutically, targeting BANF1 in tumors activates antitumor immunity via cGAS-STING signaling and enhances response to immunotherapy, suggesting its potential as a cancer therapeutic target 3.