In this regard, ultra-small IONPs with an average size of 5 nm, surface-modified with two peptides targeting Wnt/LRP5-6 and the urokinase plasminogen activator receptor (uPAR), downregulated Wnt/β-catenin signaling and marker expression of CSCs, resulting in a greater inhibition of tumor growth in a patient-derived xenograft (PDX) breast tumor model, as compared to single-targeting IONPs [89]. Here, PLAUR is linked to breast neoplasm.