TP53 and cancer: The experiment was designed so that the developed VNP-Laz strain of S. typhimurium infects three different cancer cell lines; namely; breast cancer cell line MCF-7 as a representative of non-brain cancer cells with a wild type p53; brain cancer cell line U-373 as a representative of glioblastoma cells with mutated p53; and LN-229, glioblastoma cells with wild type p53.