TP53 and colorectal cancer: A global reduction in H3K9me3 protein following doxorubicin treatment, previously characterized in the colorectal cancer cell line HCT116 [23], was clearly observed in unmodified hTERT-RPE1, retained in the TP53+/A276P line but completely absent in p53-deficient hTERT-RPE1 cells (Figure 5A).