Kawabe et al (2000) demonstrated, by clonogenic survival assay, that adenovirus-mediated p16 gene expression enhanced the radiosensitivity of non-small-cell lung cancer cells, depending on the endogenous wild-type p53 expression of the cell line. It is well established that radiation sensitivity varies with the population of the cell-cycle, and that cells at the M-phase and late G1 to the early S phase have great sensitivity (Terasima and Tolmach, 1963; Okada, 1970). Here, TP53 is linked to non-small cell lung carcinoma.