CD274 and neoplasm: IHC analysis of the tumor tissue for MHC-I and PD-L1 expression showed a significantly increased mean optical density for MHC-I in MOC1.4E8intermediate compared MOC1.3D5low (p = 0.007) and MOC1 parental tumors (p = 0.008) (Fig. 2B and supplementary Fig. S4).