The latter continues to be somewhat controversial: while increased systemic insulin might perhaps be expected to be reflected in increased brain interstitial insulin (which would be consistent with central insulin resistance), some authors have suggested, based on measurements from the cerebrospinal fluid, that patients with systemic insulin resistance may in fact have reduced central insulin (Craft et al., 1998; Engel et al., 2022; Gray & Barrett, 2018). The gene discussed is INS; the disease is Insulin resistance.