PLPP4 (phospholipid phosphatase 4) is a magnesium-independent enzyme that catalyzes the dephosphorylation of various phospholipids, with preferential activity toward diacylglycerol pyrophosphate conversion to phosphatidate, and secondary activity on phosphatidate and lysophosphatidate 1. The enzyme plays a critical role in lipid metabolism, particularly in triacylglycerol regulation and lipid droplet formation 2. PLPP4 demonstrates significant oncogenic properties across multiple cancer types. In breast cancer, overexpression promotes cell proliferation, migration, invasion, and chemotherapy resistance to doxorubicin, while enhancing adipogenic potential through increased lipid accumulation and adipocyte marker expression 23. Similarly, in lung carcinoma, elevated PLPP4 expression correlates with advanced pathological grade, tumor stage, and poor patient survival, promoting proliferation and tumorigenesis via calcium signaling pathways 4. The gene has also been identified as a biomarker in ovarian cancer bowel metastases and temporal lobe epilepsy 56. Clinically, PLPP4 expression serves as a prognostic indicator for multiple cancers and represents a potential therapeutic target, with its transcriptional regulation involving factors like CAPRIN1 in breast cancer 3.