CD274 and type 2 diabetes mellitus: The role of the PD-1/PD-L1 pathway in T2DM, more specifically in T2DM complications development, is still at its early beginnings and should be better characterized in respect to time and both micro- and macrovascular complications, as to really determine whether this immune pathway is linked to the pathophysiology of T2DM or only reflects a compensation mechanism in regards to T2DM inflammation and cell injury.