CD274 and keratoconus: ImmTOR was taken up by the vast majority of KC cells of either cytokine-secreting (F4/80+, CD11b+) or phagocytic (F4/80+, CD68+) phenotype (Figures 1A, B) and induced a tolerogenic phenotype in KCs, as evidenced by substantial increase in PD-L1 expression and decrease in CD80 and MHC class II expression that persisted for 7 days after treatment (Figures 2A–C).