Lipocalin-2 (LCN2), also known as 24p3 or neutrophil gelatinase-associated lipocalin (NGAL), is a 25 kDa protein secreted from activated neutrophils.13 Using a chemical-genetics approach, LCN2 was identified as one of PKCδ phosphorylation substrates in neutrophils.14–16 PKCδ directly phosphorylates LCN2 at Thr-115, and mediates the secretion of LCN2 from activated neutrophils in vitro and after cerebral ischemia in vivo. This evidence concerns the gene PRKCD and brain ischemia.