To compare the activities of actinomycin V on human non-small-cell lung carcinoma cells, 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) analyses were carried out to measure the cytotoxicity of actinomycin V on A549 (with wild-type p53), NCI-H1299 (p53-deficient) and normal human bronchial epithelial cells (BEAS-2B). The gene discussed is TP53; the disease is non-small cell lung carcinoma.