CD44 and cancer: Further, effectiveness of bLf-Dox conjugates against drug resistant CD44+/EpCAM+ double positive cancer stem cell enriched DU145 cells was tested, which showed that both Apo-bLf-Dox and Fe-bLf-Dox were capable of inhibiting clonogenic, migration as well as 3D growth properties of these cells (Supplementary Figure 2).