CDKN1A and neoplasm: Moreover, treatment of HCT116 tumor-bearing mice with ST7612AA1 resulted in up-regulation of P21 and ATF3 proteins, also confirmed at the transcriptional level in Figure 3B, thus suggesting that molecular pathways, activated by DNA damage events (TP53-mediated or not), or associated to a putative ER-stress response, might be involved.