The final results of this trial, including 90 breast cancer patients, were recently published and show the high negative predictive value of [89Zr]Zr-trastuzumab PET alone or in combination with [18F]FDG PET in predicting lesion-based and patient-based responses to HER2-targeted therapy with trastuzumab emtansine (T-DM1) [31,42]. Here, ERBB2 is linked to breast cancer.