Cytotoxic chemotherapy alone used to be the standard therapeutic option at the time of progression while continuation of TKI therapy by itself or in combination with chemotherapy seems to provide continued clinical benefit.[17–19] It may be in accordance with the tumor heterogeneity in the development of resistance to targeted therapies and minor tumor cell populations will still be sensitive to the previous EGFR-TKIs. The gene discussed is EGFR; the disease is neoplasm.