TP53 and cervical cancer: hsa_circ_0000263 functions as a competitive endogenous RNA to regulate the MDM4 regulator of P53 (MDM4) expression as a miR-150-5p sponge, suggesting that the regulatory axis of circ_0000263/miR-150-5p/MDM4 could play an essential role in the pathogenesis and development of cervical cancer by influencing TP53 gene expression.