At the cellular level, podocalyxin overexpression expands apical membrane domains on the free surface of epithelial breast cancer cells that are maintained in monolayer culture where it alters the subcellular localization of two associated actin-binding scaffolding proteins, NHERF-1 and ezrin [34], both of which have been implicated in breast tumor progression when they are mistargeted [35–37]. This evidence concerns the gene PODXL and breast cancer.