PPM1N is a metal-dependent serine/threonine protein phosphatase belonging to the PP2C phosphatase family, which comprises 20 mammalian isoforms 1. As a member of the PPM family, PPM1N contains a conserved catalytic core that binds manganese/magnesium ions (Mn2+/Mg2+) and functions as a single-subunit enzyme 1. PPM1N is classified within the PPM1A/PPM1B/PPM1N phylogenetic class and possesses isoform-specific regions that likely contribute to substrate recognition and functional regulation 1. At the molecular level, PPM1N regulates canonical Wnt/β-catenin and NF-κB signaling pathways 2. The gene is involved in controlling diverse cellular functions including cell cycle regulation, differentiation, immune responses, and metabolism 1. PPM1N has been identified as a novel eye gene involved in visual functions in mice 3. In reproductive biology, PPM1N expression is modulated in the endometrium during estrous cycles and hormonal treatments, influencing embryo development through Wnt/β-catenin signaling 2. Clinical significance of PPM1N extends to cancer detection; it serves as a hypermethylated biomarker in urothelial cancer, with methylation analysis of PPM1N contributing to a diagnostic model achieving 94.44% sensitivity and 93.52% specificity for non-invasive UC detection 4. Dysregulation of PPM1N, like other PPM phosphatases, may contribute to various human diseases through abnormal cellular responses 1.