Isolated mortalin peptides and antibodies are provided. Accordingly there is provided an isolated peptide comprising no more than 30 amino acids having a mortalin amino acid sequence and being capable of killing cancer cells and/or enhancing complement activity； also provided is an antibody comprising an antigen recognition domain having an amino acid sequence which binds mortalin and enhances complement-dependent cytotoxicity (CDC). Also provided are compositions and methods for inhibiting mortalin activity, killing a cell and treating a disease associated with a pathological cell population.
