PPB is formed by a ligand for folate receptor capable of targeting tumor cells, an infrared fluorochrome pyropheophorbide α (Pyro), a black hole quencher 3 (BHQ3), and a peptide linker (GDEVDGSGK) specific for caspase-3 (in fact it contains the tetrapeptide motif DEVD for caspase-3 recognition). This evidence concerns the gene CASP3 and neoplasm.