CD274 and cancer: Human head and neck (177), lung (178), and colorectal (179) cancer cells that have CSC-like characteristics (CD44high/CD133high) were shown to preferentially express PD-L1 compared to CD44low/CD133low cancer cells in immunocompromised mouse models either inoculated with a patient-derived xenograft or human cancer cell lines mixed with Matrigel®, respectively.