Starting from the NGR parameter values, progressive degrees of clinical worsening (up to T2DM) were simulated by changing some model parameters, such as insulin sensitivity (k2), average net hepatic glucose production (k ̄3), and other parameters related to the mechanisms of insulin production (average ρn, average D ̄n, and g1/2). The gene discussed is INS; the disease is type 2 diabetes mellitus.