They showed that liposomes loaded with saporin and functionalized with cell penetrating peptides (Tat 48-57, cell-permeable peptide, derived from HIV-1 transactivator of transcription (Tat) protein residue 48-57), some of which are connected via a flexible linker with photosensitizers, effectively bind to and are internalized into tumor cells in vitro. This evidence concerns the gene TAT and neoplasm.