We speculate that this connection is also consistent with the observation that Tibetans show threefold lower prevalence of diabetes than other Chinese ethnic groups (Wang et al. 2017), and the Tibetan population carries a high frequency of a hypoxia-inducible factor (EPAS1) gene variant that is associated with adaptive lower hemoglobin (Huerta-Sánchez et al. 2014; Simonson et al. 2010). This evidence concerns the gene EPAS1 and diabetes mellitus.