CD274 and squamous cell carcinoma: The pathology of the mass showed that it has been highly-moderately differentiated squamous cell carcinoma, and the immunohistochemistry demonstrated that malignant cells were positive for CK-pan, CK5/6, EGFR, Ki67 (35%), P16 (small focus positive), P40, p53, PD-L1 (22C3) (CPS:5) immunohistochemical markers (Figure 2J).