Besides the environment, T2DM is a multifactorial disease involving genetic influence that has a “nature vs. nurture outcome.” The pathophysiological changes of diabetes are characterized by (1) β-cell dysfunction in the periphery (e.g., the liver, skeletal muscle, and adipose tissue) and (2) inflammation-dependent ROS generated locally by tissue or due to immune cells interacting with the insulin receptor (IR) as well as their downstream signalling pathways, resulting in a failure to respond adequately to insulin levels. The gene discussed is INSR; the disease is type 2 diabetes mellitus.