HSPG2 and type 2 diabetes mellitus: Future studies exploring the enzymatic property of SMSr may contribute to understanding of the novel DG/PA metabolic pathway in the ER membrane and the pathogenetic mechanisms of various diseases related to DGKδ, type 2 diabetes (25, 26) and obsessive–compulsive disorder (27, 28) and, probably, to PC-PLC, atherogenesis, inflammation, and carcinogenesis (12, 40, 59).