GPATCH2 (G-patch domain containing 2) is a nuclear protein that functions as a regulatory cofactor for RNA-dependent ATPases. It enhances the ATPase activity of DHX15 and interacts with hPrp43 to potentiate its enzymatic function 1, positioning it as a modulator of RNA processing. GPATCH2 is predominantly localized to nuclear specks and the nucleus 2. In cancer biology, GPATCH2 plays a multifaceted oncogenic role. In hepatocellular carcinoma, GPATCH2 is markedly upregulated and promotes tumor progression through a YY1-GPATCH2-SNAI2 axis, driving HCC cell proliferation, migration, and invasion while suppressing epithelial markers like CDH1 3. Similarly, in breast cancer, GPATCH2 overexpression is prevalent and its knockdown suppresses cancer cell growth, suggesting essential roles in oncogenic transformation 1. Conversely, GPATCH2 exhibits tumor-suppressive functions in non-transformed contexts. Overexpression of GPATCH2 in 293T cells inhibits NF-κB transcription and cell proliferation by blocking G1-S phase transition 2, indicating cell-type-dependent regulatory roles. GPATCH2 is classified as a cancer/testis antigen with predominant testicular expression 12. Genetic studies associate GPATCH2 variants with age-related glomerular pathology in mice 4, suggesting broader roles in tissue homeostasis.