THAP5 (THAP domain containing 5) is a zinc finger transcription factor that functions as a DNA-binding transcriptional repressor 1. The protein contains a THAP domain and exhibits sequence-specific DNA-binding activity, capable of recognizing and binding specific DNA motifs to repress transcription of target genes 1. A primary regulatory role of THAP5 involves cell cycle control. THAP5 overexpression causes cell cycle arrest at the G2/M phase in human cell lines 2, and it is characterized as a cardiac-specific inhibitor of cell cycle progression 2. THAP5 is predominantly expressed in the human heart, with lower expression in brain and muscle 2. THAP5 also functions in apoptotic pathways. The protein is induced by DNA damage (UV irradiation and cisplatin treatment) 1, and induction correlates with increased apoptotic cell death in melanoma cells 1. During apoptosis, THAP5 is cleaved and degraded by the mitochondrial protease Omi/HtrA2 2. Clinically, THAP5 protein levels substantially decrease in myocardial infarction areas of coronary artery disease patients 2, suggesting potential involvement in heart disease pathology. Additionally, THAP5 was identified as a novel MET fusion partner in rare cases of non-small cell lung cancer 3, and as a convergent schizophrenia susceptibility gene in cross-tissue transcriptomic studies 4.