TP53 and cancer: In agreement with the EMSA result that mutant p53 C238Y bound to MP53BS in the CTNNB1 protomer (Fig. 3j), knockdown of this mutant by shRNAs largely decreased β-Catenin expression in LuCaP 23.1 PDX-derived organoids (PDXO) (Fig. 7e), indicating that LuCaP 23.1 is an ideal PDX model to test anti-cancer efficacy of inhibition of the β-Catenin-LEF/TCF pathway.