To further confirm that MeCP2 might promote breast cancer cell proliferation by suppressing RPL11/RPL5 expression and promoting the E3 ubiquitin ligase activity of MDM2, MeCP2 overexpression vector was co-transfected with RPL11 or RPL5 overexpression vectors or MDM2 inhibitor (Nutlin3) into MCF7 cells. This evidence concerns the gene MECP2 and breast cancer.