LPIN1 encodes lipin 1, a magnesium-dependent phosphatidate phosphatase that catalyzes conversion of phosphatidic acid to diacylglycerol, controlling fatty acid metabolism during triglyceride and phospholipid biosynthesis 1234. Beyond its enzymatic role, lipin 1 functions as a nuclear transcriptional coactivator regulating lipogenic gene expression through the mTORC1-SREBP pathway 5. mTORC1 phosphorylation controls lipin 1 nuclear localization, where dephosphorylated lipin 1 promotes SREBP-mediated lipid synthesis; inhibition of mTORC1 impairs SREBP function in a lipin 1-dependent manner, protecting against hepatic steatosis 5. Extracellular mechanical cues regulate lipid metabolism through lipin 1-mediated control of SREBP activation, independent of YAP/TAZ and mTOR pathways 6. FXR agonists reduce hepatic mono- and polyunsaturated fatty acids by repressing Lpin1 expression 7. Recently, the PI3K/AKT/mTOR/LPIN1 pathway was identified as protective against hepatocyte ferroptosis in sepsis 8. LPIN1 mutations cause autosomal recessive acute recurrent myoglobinuria, though common genetic variation shows limited association with obesity or insulin resistance in human populations 9. LPIN1 emerges as a ferroptosis-related biomarker in diffuse large B-cell lymphoma pathogenesis 10.