TP53 and neoplasm: Lastly, to assess the specificity of P1C1TM for tumour cells expressing mutant p53 in vivo, xenografts of either MDA-MB-231 and HT29 or SaoS2 and HT29 cells were introduced into the opposite flanks of immunodeficient NOD-scid IL2rgnull (NSG) mice (Supplementary Fig. 7a, b).