TP53 and non-small cell lung carcinoma: To determine whether the enhanced susceptibility to bortezomib was due to the presence of p53 R273H, we used an isogenic cell line set in which the p53 null human NSCLC cell line H1299 was stably transfected to either express a null vector control, the p53 R273H mutant or a wildtype p53 rescue construct.