MEX-3 RNA binding family member A (MEX3A), is a subtype of RBPs that functions in various RNA metabolism-related processes including mRNA stability,5,6 and miRNA transport between the nucleus and cytoplasm.7 Accumulating evidence has suggested the involvement of MEX3A in cancer progression such as lung cancer,6 glioma,8 and breast cancer.9 Multiple studies have demonstrated that MEX3A takes part in intestinal differentiation and cell stemness.10 MEX3A labels the slowly cycling subpopulation of Lgr5+ intestinal stem cells. Here, MEX3A is linked to breast cancer.