Examples include imaging human epidermal growth factor receptor 2 (HER2) using the tracer 111In-trastuzumab, vascular endothelial growth factor A (VEGFA) using 89Zr-bevacizumab7 and oestrogen receptor expression using [18F] fluoroestradiol (18F-FES).8,9 However, functional cancer imaging has long exploited the high metabolic requirements of tumour cells for clinical purposes and hence significant opportunity exists to use these techniques to image ‘cancer metabolism’. This evidence concerns the gene ERBB2 and cancer.