CD274 and urothelial carcinoma: To confirm the significance of Meflin expression in CAFs in response to ICB therapy, we subcutaneously transplanted C57BL/6 WT and Meflin KO female mice with MB49, a syngeneic urothelial carcinoma cell line [32], followed by intraperitoneal (i.p.)administration of anti-PD-L1 antibody or isotype control IgG (Fig. 1e).