TP53 and digestive system cancer: In fact, a wtp53-dependent growth inhibitory effect could be evidenced for SLMP53-2, which showed a two-fold reduction in the IC50 value in HCT116 colon tumor cells expressing wtp53 (IC50 of 8.4 ± 1.1 μM) compared to its isogenic p53-null derivative (IC50 of 17.7 ± 2.3 μM) (Figure S10B).