KLF4 and neoplasm: Recently, RNAa has been shown to activate genes that are capable of suppressing tumor cell growth (p21, E-cadherin, p53 and NKX3.1), triggering angiogenesis (VEGF), influencing stem cell maintenance (KLF4 and OCT4) and regulating endocrine or metabolism levels (PR and LDLR) [10, 12–14, 17, 21].