Protein transduction domain (PTD) or cell-penetrating peptide (CPP) can be used to deliver a wide range of molecular cargoes including peptides, proteins, nucleic acids, nanoparticles, and other therapeutic agents. One major limitation is their lack of tissue specificity or tropism, as they can facilitate cargo delivery across a broad range of cell types. In the present hypothesis, I propose a ligand-guided strategy to address this limitation and improve the cell specificity/