TP53 and lung carcinoma: To determine the impact of expressing a TAD mutant of the human p53-R273H in the human lung cancer cell line H1299 (p53 null) on tumorigenicity, we first isolated cancer stem-like cells as spheroids (Fig. 2a) in low serum media41–43 from H1299 cells stably transfected with vector alone, expressing p53-R273H, and p53-L22Q/W23S/R273H.