Several investigators have reported depressed circulating Klotho levels in subjects with type 1 diabetes (T1D) (Keles et al., 2016; Tarhani et al., 2020; Zubkiewicz-Kucharska, 2021); and type 2 diabetes (T2D) especially when there is advanced disease (Nie et al., 2017; Fountoulakis et al., 2018; Zhang and Liu, 2018). The gene discussed is KL; the disease is type 2 diabetes mellitus.