Specifically, the high-affinity variant H3B1 (0.56 nM) was shown to mediate the greatest level of cell cytotoxicity against tumor cell lines with disparate levels of HER2 expression, followed by the moderate-affinity variant C6.5 (23 nM) and the low-affinity G98A (270 nM). This evidence concerns the gene ERBB2 and neoplasm.