Figure 2: MiR-1 and miR-133 in heart development. During cardiomyocites differentiation, expression levels of miR-1 and miR-499 increase. miR-1 induces differentiation by inhibiting the expression of HDAC4, Delta like l (Dll1) and Hand2 which in turn regulate the expression of cardiac specific genes [60]. miR-499 negatively regulates the expression of Sox6 and Rod1 [70]. miR-133 inhibits differentiation inhibiting the expression of SRF, conversely promoting cell proliferation [60].