PSMA6 and obesity due to melanocortin 4 receptor deficiency: Since polygenic obesity is a major risk factor for T2DM and given the association between PSMA6 and T2DM, we hypothesize an association between childhood obesity and the PSMA6 gene as well as the PSMA3 proteasomal gene, which interacts with the PSMA6 gene in forming structurally linked proteasomes [19].