In a study attempting to confirm this hypothesis, HER2− tumour-bearing mice showed bone uptake after injection of 89Zr-labelled DFO-trastuzumab or DFOcyclo*-trastuzumab similar to that in HER2+ tumour-bearing mice, but about 4.5 times lower tumour uptake. This evidence concerns the gene ERBB2 and neoplasm.