Insulin lispro is the active ingredient of Humalog® (Ly-Lis; Lilly).3 Humalog was the first rapid-acting insulin approved and marketed in the EU, the US, and many other countries worldwide, and is used in the treatment of both patients with type 1 diabetes mellitus (T1DM) and T2DM. The gene discussed is INS; the disease is type 2 diabetes mellitus.