However, when we xenografted the aggressive R273C, R248W, and Y220C cells and the less aggressive Y234C cells (n = 2 each) in the NOD/SCID mice, no detectable tumor was observed up to 10 months post injection, whereas the control MDA-MB-231 cells formed tumors that metastasized to the lung and the liver within 2 months (unpublished results), agreeing that TP53 mutation alone is not sufficient to enable tumor formation in vivo74,75. This evidence concerns the gene TP53 and neoplasm.