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. Here, MTNR1B is linked to type 1 diabetes mellitus.