ZFY is a Y-linked zinc finger transcription factor that serves as a sequence-specific DNA-binding protein recognizing the consensus sequence 5'-AGGCCY-3' 1. As a probable transcriptional activator, ZFY functions in positive regulation of transcription through RNA polymerase II, binding to chrY and cis-regulatory regions [UniProt GO annotations]. ZFY plays a key role in sex chrY-mediated regulation of autosomal gene expression; recent studies demonstrate that ZFY, along with its homologous X-linked counterpart ZFX, modulates approximately 21% of all genes expressed in lymphoblastoid cells and fibroblasts, with Y chromosome Y on autosomal expression remarkably similar to those of the inactive X chrY 23. Clinically, ZFY expression is altered in prostate adenocarcinoma, where ZFY transcripts were detected in 20 of 31 tumors by RT-PCR but absent in normal prostate tissue, suggesting potential involvement in malignant development 4. Historically, ZFY was investigated as a candidate for the testis-determining factor, though evidence now indicates ZFY and the true sex-determining locus (TDF) are distinct genetic entities 51. ZFY's precise molecular targets and complete functional role in sex determination remain incompletely characterized.