Future studies will further identify the biochemical properties of MARCH8 in mediating the interactions with CD44, STAT3, and other new targets, map their ubiquitination sites in connection to lysosome and proteasome degradation pathways, and elucidate the interplay with phosphorylation-mediated alterations of cell fate, stem-cell functions, and metastasis in breast cancer, as well as other cancers. Here, STAT3 is linked to breast cancer.