A recent in vitro study demonstrated that of the 9 non-small cell lung cancer (NSCLC) cell lines examined, the PC9 cell line was most sensitive to the effect of gefitinib when assayed under basal growth conditions for EGFR phosphorylation and activation of EGFR downstream effectors such as AKT and those in the ERK1/2 pathway, which are required for its survival and proliferation [11]. Here, EGFR is linked to non-small cell lung carcinoma.