MAPK3 and breast cancer: During the course of this study, Neupane et al. reported that MeCP2 activates MAPK signaling in breast cancer, cervical cancer and lung cancer.31 Different from their work, our study has characterized the role of MeCP2 in GC, a previously unstudied area, and most importantly, we have revealed for the first time that miR-638-mediated MeCP2 activates the MEK1/2–ERK1/2 signaling pathway by upregulating GIT1 expression in GC.