Biodistribution analysis conducted by Pruszynski et al. [153] also found the uptake of [225Ac]Ac-DOTA-2Rs15d in SKOV-3 tumour bearing mice to be 8-fold greater than that of MDA-MB-231 after 2 h, and further increased to 15-fold after 48 h, indicating the specificity of [225Ac]Ac-DOTA-2Rs15d for HER2. This evidence concerns the gene ERBB2 and neoplasm.