Although the molecular mechanisms underlying altered beta-cell secretion and insulin kinetics in T2DM patients are unknown, there is clear evidence for genetic (and epigenetic) as well as environmental factors such as physical inactivity and overweight/obesity, which are more prevalent in Africans and Europeans (Kolb and Martin, 2017; Ali et al., 2018; Dendup et al., 2018) (Table 1). Here, INS is linked to type 2 diabetes mellitus.