DPP4 and bullous pemphigoid: The pathogenesis of dipeptidylpeptidase 4 inhibitors associated bullous pemphigoid remains to be determined; alteration in the correct cleavage of BPAg2 (resulting in modification of its antigenicity and function) by dipeptidylpeptidase 4 inhibitors-associated plasmin inhibition has been postulated as a potential mechanism [40].