DUSP4 and familial dilated cardiomyopathy: Further, dual specificity phosphatase 4 (DUSP4) is upregulated by MAPK3/1 (ERK1/2) and was shown to result in DCM via metabolic disturbances and autophagy inhibition through the AKT1/MTOR pathway [89], pointing to the complex interplay of MAPK3/1 (ERK1/2) and AKT1 in autophagy.