CD274 and head and neck cancer: PD-L1 expression showed insignificant predictiveness in ovarian cancer (HRD = 0.23, Pi = 0.25), head and neck cancer (HRD = 0.09, Pi = 0.62), NSCLC (HRD = 0.08, Pi = 0.21), and bladder cancer (HRD = 0.04, Pi = 0.76).