For EGF, a study showed that PD-L1 expression increased in an EGFR-dependent manner when EGFR signalling was activated and decreased when EGFR signalling was blocked in esophageal squamous cell carcinoma, and this was through EGFR-PI3K-AKT, EGFR-Ras-Raf-Erk, and EGR-PLC-gamma signalling pathways [26]. The gene discussed is EGFR; the disease is esophageal squamous cell carcinoma.