AKT1 and hyperhomocysteinemia: On the contrary, mice or rats with hyperhomocysteinemia (resulting from a high-methionine diet) have decrease Dyrk1A protein levels both in the liver and the brain (Hamelet et al., 2009; Rabaneda et al., 2016) and consequently decreased phosphorylation of Akt (Liu et al., 2010, 2011; Figure 5).