CD276 and retinoblastoma: In different diseases, B7H3 is differentially expressed in the stroma and tumor cells; for example, in colorectal and pancreatic cancers, a higher percentage of B7H3 was positive in stroma than in tumor cells, whereas in prostate cancer, B7H3 expression was higher in tumor cells than in stroma; in RB tumors, B7H3 was observed in mutually exclusive expression in tumors and blood vessels, which has not been reported in other cancer types.