Similarly, transcripts of candidate genes for type 2 diabetes (Blk, C2cd4a, C2cd4b, Cdkn2a, Hnf1a, Mtnr1b, Pou5f1, Slc30a8) and type 1 diabetes (Cd69, Il2, IL27) were not expressed in the brain. This evidence concerns the gene MTNR1B and type 2 diabetes mellitus.