Biodistribution experiments showed that tumor uptake values of 64Cu-DOTA-labeled monomeric and dimeric Her-2 antibodies were 6.12 ± 1.44% and 1.46 ± 0.50% ID/g, respectively, in nude mice (n = 3 each) at 4 h post injection. This evidence concerns the gene ERBB2 and neoplasm.