Other glucose-lowering therapies may be combined with insulin in those with type 2 diabetes, as combined therapy in this condition may achieve better blood glucose control than insulin alone. In contrast non-insulin therapy is usually ineffective in type 1 diabetes, likely due to differences in endogenous insulin secretion. Among the commonly used glucose-lowering treatments which are licensed for combined therapy with insulin in type 2 diabetes are the dipeptide peptidase 4 (DPPIV) inhibitors. They have multiple mechanisms of action that include potentiation of beta cell insulin secretion and suppression of glucagon. The relative importance of these mechanisms to treatment response is unclear.