APOE and type 2 diabetes mellitus: The presence of ApoE ε4 gene and upregulation of platelet GSK‐3β activity are respectively correlated with the occurrence of mild cognitive impairment in T2DM patients [26], and individuals carrying the ApoE ε4 allele exhibited elevated GSK‐3β activity in platelets and more severe cognitive impairment compared with those with the ApoE ε3 allele within a cohort of T2DM patients [27, 28].