CXCR4 and neoplasm: Cells were treated with anti-CXCR4 antibody for 30 min at 4° C and then with normal human serum (NHS), or heat inactivated normal human serum (HIS) [16], plus or minus SMR peptides for 60 min at 37° C. In the presence of NHS, both of SMRwt peptides significantly induced tumor cell death via complement.