ESR2 and neoplasm: To test the ability of Erb-hcAb-RNase of inducing CDC against ErbB2-positive tumour cells, SKBR3 target cells were incubated for 6 h with Erb-hcAb-RNase (10 or 30 μg ml−1) in the absence or in the presence of human serum as a source of complement.