TP53 and cancer: Three human cancer cell lines–HCT116 (WT TP53), HDQ-P1 (TP53-R213X) and H1299-p53 R213X (TP53-null H1299 cells stably expressing TP53-R213X cDNA) were exposed to 10 μM mefloquine in the absence or presence of 50 or 100 μM G418.