HGF and small cell lung carcinoma: Other genomic mutations in tumor cells that may contribute to EGFR‐TKIs resistance include amplification of the MET oncogene [10], overexpression of hepatocyte growth factor (HGF), amplification of the ERBB2 gene [11], aberrant downstream pathways (e.g., AKT mutations and PTEN loss), impairment of the EGFR‐TKIs‐mediated apoptosis pathway (e.g., BCL2L11/BIM deletion polymorphism), and histological transformation to small cell lung cancer (SCLC) [9].