FKGK 18 is an inhibitor of group VIA (GVIA) calcium-independent phospholipase A2 (iPLA2). It inhibits GVIA iPLA2 by 99.9% at 0.091 mole fraction in a mixed micelle activity assay and is selective for GVIA iPLA2 over GIVA cPLA2 and GV sPLA2 where it shows 80.8 and 36.8% inhibition, respectively. FKGK 18 inhibits iPLA2β activity in cytosolic extracts from INS-1 cells overexpressing iPLA2β (IC50 = ~50 nM) as well as iPLA2γ activity in mouse heart membrane fractions (IC50s = ~1-3 μM). It inhibits glucose-induced increases in prostaglandin E2 production and insulin secretion in human pancreatic islets when used at a concentration of 10 μM and inhibits thapsigargin-induced apoptosis in INS-1 cells overexpressing iPLA2β in a concentration-dependent manner. FKGK 18 (20 mg/kg, 3 times per week) reduces blood glucose levels in an intraperitoneal glucose tolerance test, decreases the incidence of diabetes, and increases serum insulin levels in non-obese diabetic (NOD) mice.