KRT16 and neoplasm: We have also shown that lipopolyplexes formulated with a non-targeting K16 peptide, or with a peptide with a randomized targeting sequence, will have greatly reduced transfection, since the receptor-mediated uptake pathway will no longer be active.30 Since the Y-I targeting peptide gave a higher extent of lipopolyplex delivery to the tumour cells, we further optimized this complex to increase the expression of Picchu-X.