CD274 and breast carcinoma: SHH (100 μg/mL) treatment significantly reduced PD‐L1 expression in several cancer cell lines: NSCLC (A549 and HCC‐366), breast cancer (MCF‐7 and MDA‐MB‐231), colorectal cancer (SW620), kidney cancer (A498), and ovarian cancer (SK‐OV‐3 and NCI/ADR‐RES) (Figure 1A,B, p < 0.05).