The present invention addresses the problem of providing: a fusion protein or conjugated protein having excellent cell membrane permeability, containing a partial peptide derived from human, and suitable for intracellular delivery an intracellular delivery carrier comprising such a fusion protein or conjugated protein a partial peptide a cell membrane permeation enhancer comprising the partial peptide DNA and a vector. The fusion protein or conjugated protein has a partial peptide comprising at least seven consecutive amino acid residues of an amino acid sequence encoded by a predetermined DNA, and a ligand directly or indirectly bound to the partial peptide and having the capability of binding to cell surfaces. The ligand is preferably an antibody. The intracellular delivery carrier comprises the fusion protein or conjugated protein. The cell membrane permeation enhancer comprises the partial peptide.
