CD274 and type 1 diabetes mellitus: We first tested the effect of pharmacological modulation with PGE2 by FACS analysis, and our data revealed a slight increase in PD-L1 expression, although not significant, in cultured CD34+ cells from T1D and healthy control patients, with the latter showing a higher percentage of PD-L1 expression as compared to cells from T1D patients (Figures 2C,D).