Furthermore, the inhibition of the EGF signaling by EGFR small interfering RNA (siRNA), anti-EGFR antibody (cetuximab), and EGFR-TKi (Iressa) determined an increase in the sensitivity to RET inhibitors in lung cancer cells carrying CCDC6-RET fusion [123] (Fig. 3). This evidence concerns the gene EGFR and lung cancer.