Notes: C18 Ceramide-d3 (d18:1/18:0) is intended for use as an internal standard for the quantification of C18 Ceramide (d18:1/18:0) (Item No. 19556) by GC- or LC-MS. C18 Ceramide is an endogenous bioactive sphingolipid. It is the primary short-chain ceramide found in brain tissue whose synthesis is regulated by longevity-assurance homologue 1 (Lass1) in mice.{40029} Increased expression of C18 ceramide reduces cell growth in UM-SCC-22A squamous cell carcinoma cells.{13918} It is selectively downregulated in 32 human head and neck squamous cell carcinoma tumor tissues as compared to non-squamous tumor tissues. C18 Ceramide concentration is significantly higher in muscle tissue of type 2 diabetic patients compared with non-diabetic patients and is positively correlated to body mass index and inversely related to insulin sensitivity.{40030} [Matreya, LLC. Catalog No. 2201]