Based on limited published evidence, ZNF777 is a KRAB zinc finger transcription factor that functions as a transcriptional repressor 1. It localizes to the nucleus and contains a conserved DUF3669 domain that mediates protein-protein oligomerization and contributes to transcriptional repression activity 1. ZNF777 inhibits cell proliferation at low cell density through zinc finger domain-dependent down-regulation of NIBAN1/FAM129A, leading to p21 induction 2. Its repressor activity depends on intact DUF3669 and variant KRAB domain configuration rather than canonical KRAB-TRIM28 interactions 1.