ERBB2 and neoplasm: As a result of this analysis, a comparison of [89Zr]Zr-trastuzumab (T/B): [111In]In-IgG (T/B) ratios against the HER2 expression levels (Bmax) for each tumour type, which also revealed a strong correlation with empirically determined HER2 expression levels than [89Zr]Zr-trastuzumab: [111In]In-IgG tumour uptake ratios alone (R = 0.995, P = 0.0025 vs. R = 0.94, P = 0.029, respectively; Fig. 6A–D).