THAP3 is a transcriptional regulator containing a THAP-type zinc finger domain that functions as a component of a THAP1/THAP3-HCFC1-OGT complex regulating transcriptional activity 1. The protein associates with the transcriptional coactivator HCF-1 through a conserved HCF-1-binding motif and interacts with O-GlcNAc transferase (OGT), linking it to cell cycle regulation 1. THAP3 recruits the histone methyltransferase SMYD3 to OXPHOS genes, promoting H3K4me3 deposition and upregulating mitochondrial respiratory gene expression in hepatocellular carcinoma 2. Genetically, THAP3 variants are associated with aggressive prostate cancer in familial disease contexts 3. Network analyses of oligodendrogliomas with 1p/19q co-deletion identify THAP3 as a putative oncogenic driver within this chr1 region 4. In myeloid leukemia, THAP3 expression correlates with CD45 levels, and modulating this axis enhances chemotherapy sensitivity 5. These findings position THAP3 as a multifunctional epigenetic regulator influencing cellular respiration, proliferation, and cancer progression across multiple malignancies.