Since apoM is associated with changes in lipid metabolism and cardiovascular diseases and S1P is important for inflammation, lymphocyte migration, endothelial integrity, and angiogenesis, several experimental studies have attempted to explore whether apoM and/or S1P contribute to the development of diabetes (e.g., by inducing glucose or insulin resistance) and the associated complications (e.g., cardiovascular disease, neuropathy, retinopathy, and nephropathy). Here, APOM is linked to neuropathy.