It is noteworthy that decreased expression of HMG20A has been found in islets from T2D donors when compared with islets from normoglycemic donors [123], suggesting that low levels of HMG20A may result in the activation of the inhibitory action of the LSD1/CoREST complex, causing the dedifferentiation of β-cells. The gene discussed is HMG20A; the disease is type 2 diabetes mellitus.