PNPLA3 and type 2 diabetes mellitus: Another example is the colocalization between a GWAS signal for type 2 diabetes with the missense lead variant rs738409 in the PNPLA3 gene, a well-established locus for non-alcoholic fatty liver disease34, and a trans-pQTL for ADP Ribosylation Factor Interacting Protein 2 (ARFIP2) (Fig. 6e), which is strongly downregulated in type 2 diabetes patients in AGES (Fig. 6f)18.