To further clarify the molecular mechanisms underlying Gefitinib-induced apoptosis enhanced by FZKA in lung cancer, the expression of Bcl-2 family members including pro-apoptotic proteins (Bcl-2 and Mcl-1 are pro-apoptotic) and anti-apoptotic proteins (Bax and Bim are anti-apoptotic) in A549 and PC9 cells treated with FZKA and Gefitinib were examined. Here, MCL1 is linked to lung carcinoma.