RFE identified 8 features that could be used to distinguish HER2-zero expression from HER2-low/positive expression, including 3 clinical features (age, CA125, CA153), 2 CT features (CTmean and tumour min diameter) and 3 PET metabolic features (SUVmax, SUVmean, and SUVpeak). Here, ERBB2 is linked to neoplasm.