THEM2 (Thioesterase Superfamily Member 2) belongs to the hotdog-fold enzyme superfamily but its biological function remains unknown. It comprises of a single hotdog fold thioesterase domain. Under biological conditions, THEM2 probably functions as a homotetrameric long-chain acyl-CoA thioesterase. Accordingly, it has been designated as the 13th member of the mammalian acyl-CoA thioesterase family, Acot13. THEM2 occurrence is most predominant in the kidney and is regulated by the hepatocyte nuclear factor 4alpha which in turn might play an important role in renal cell carcinoma.