In this context, we tested here the unexplored capacity of the human ligand EPI-X4 as a tumor-homing peptide in protein-based self-assembling NPs and their potential, together with T22, to form biparatopic agents aimed to enhance the specificity in targeting and internalization into CXCR4-overexpressing tumor cells. The gene discussed is CXCR4; the disease is neoplasm.