IL17A and breast angiosarcoma: As the ubiquitously expressed ectopeptidase CD26/DPP4 is involved in numerous inflammatory and autoimmune conditions18,34, we aimed to investigate the expression and regulation of CD26/DPP4 in human BA as well as the effect of DPP4 inhibition on the production of the predominant cytokines IL-17 and IFN-γ in experimental BA.