The phosphorylation of ERK1/2 (also referred to as p44/42 mitogen-activated protein kinase, MAPK) on its activation sites (Thr202/Tyr204) was significantly downregulated in patients with DCM, IHD and IHD-T2DM (all P < 0.05) compared to controls, showing a reciprocal change in contrast to SGLT1 protein expression (Fig. 3b). Here, MAPK3 is linked to type 2 diabetes mellitus.