Given the pivotal and neuroprotective role of insulin-signaling in the brain and that T2DM is one of the greatest known risk factors for AD and PD, it is no surprise that its early desensitization in the CNS, believed to predominantly occur in response to chronic inflammation, promotes the development of AD and PD (see Holscher, 2019 for further information) (Blazquez et al., 2014; Werner and LeRoith, 2014; Holscher, 2020). Here, INS is linked to Parkinson disease.