PDPN and breast cancer: When migration of fluorescently labeled MDA-MB-231 and MCF7 breast cancer cells co-cultured with MSU1.1 PDPN fibroblasts overexpressing podoplanin or control MSU1.1 NC fibroblasts was analyzed, no differences in the numbers of migrating tumor cells were found between these co-cultures (Fig 1A and 1B).