TP53 and cancer: Loss of p53 function can lead to downregulation of miR-34a; however, miR-34a expression also tends to be silenced due to aberrant CpG methylation of its promoter in many types of cancer, including breast, prostate, lung, colon, kidney, bladder, pancreatic, and ovarian cancer (Corney et al., 2010; Kong et al., 2012; Lodygin et al., 2008).