LPIN is a gene family identified recently that can induce extreme states of adiposity. The gene family includes at least three members LPIN 1, LPIN 2 and LPIN 3. The proteins that they encode are named lipin,which carry out similar functions in different tissues. Members of the lipin protein family as a phosphatidate phosphatase play a role in the biosynthesis of triglyceride and phospholipid, and also act as an inducible transcriptional coactivator in conjunction with peroxisome proliferator-activated receptor γ (PPAR γ) coactivator-1α and PPARα that modulates the expression of fatty acid oxidation gene. So they have dual roles in lipid biosynthesis and gene expression, therefore influencing lipid metabolism and glucose homeostasis. Mutations in LPIN may be associated with insulin resistance, obesity, type 2 diabetes mellitus and metabolic syndrome. Lipin may be a new useful target in treatment of insulin resistance.