TP53 and neoplasm: In addition, targeting the promoter of HPV-16 E6/E7 using the similar approach in SiHa cells also inhibited the mRNA and protein expression levels of E6/E7 and up-regulated the expression of tumor suppressors p53 and p21, which inhibited the in vitro proliferation of SiHa cells and the in vivo growth of a subcutaneously transplanted tumor in a NOD/SCID tumor mice model [59].