Glargine (A21Gly, B31Arg, B32Arg human insulin), which differs from human insulin by replacing asparagine with glycine in position 21 of the A-chain and by carboxyterminal extension of B-chain by 2 arginine residues, is widely used as a long-acting insulin analogue in the treatment of DM. The gene discussed is INS; the disease is diabetes mellitus.