By exposing fresh NSCLC tissues to X-rays, the changes in UNC5H4, p53 wild type (wt), p53 mutant type (mt) and, in particular, caspase 3 expression, were observed in order to evaluate whether UNC5H4 expression may represent an index for the radiosensitivity of NSCLC patients. This evidence concerns the gene CASP3 and non-small cell lung carcinoma.