CDKN1A and neoplasm: We confirmed that Mithramycin was able to induce p21 gene expression in HT1080 cells, but failed to reduce basal c-Myc levels suggesting the possibility that augmentation of tumor suppression genes rather than suppression of proto-oncogenes may mediate Mithramycin’s effects in HT1080 cells (Fig. 13B; Sleiman et al., 2011b).