However, a recent study reported that EGF was associated with PD-L1 transport, in which, the PD-L1 expression in cancer cell lines of non-small cell lung carcinoma (NSCLC) was shown to be enhanced by EGF treatment using flow cytometry analysis, and inhibition of EGFR by EGFR-tyrosine kinase inhibitors or EGFR small interfering RNA (siRNA) blocked EGF-induced PD-L1 overexpression in NSCLC cell lines [27]. Here, EGF is linked to non-small cell lung carcinoma.