ANXA5 and neoplasm: A significantly higher (21%) binding in the treated cells was observed with [124I]m-SIB-Annexin V. The binding of [124I]m-SIB labelled Annexin V to camptothecin treated cells was blocked (68%) by a 100-fold excess of unlabelled Annexin V. Inversely, in a study by Collingridge et al., 124I-m-SIB Annexin V failed to detect apoptosis in mice with 5-FU-treated RIF-1 tumours [14].