EGFR and head and neck squamous cell carcinoma: CAFs from chemoresistant HNSCC patients protect cancer cells by activating PI3K/AKT/p65 signaling, upregulating TGF-α, inducing the EGFR/Src/signal transducer and activator of transcription 3 (STAT3) pathway, and inhibiting apoptosis through the p53/caspase-3 pathway [52].