EGF and breast cancer: One of the mechanisms described, by which the glycosylation of PD-L1 can be achieved in breast cancer cells, involves the activation of the epidermal growth factor receptor (EGFR) signaling through binding of the epidermal growth factor (EGF) and the concomitant overactivation of the β-1,3-N-acetylglucosaminyl transferase (B3GNT3) [149].