A larger study using post-mortem examinations of the brain in AD cases demonstrated that the hippocampal formation and cerebellar cortex of patients with AD compared to age-matched controls exhibited markedly reduced responses to insulin signaling in IRS-1/IRS-2 and PI3K pathways, seemingly irrespective of T2DM status and total INSR protein level [10]. Here, INS is linked to type 2 diabetes mellitus.