ERBB2 and neoplasm: Interestingly, [68Ga]Ga-labelled HeA2_1, HeA2_3 and negative control aptamer uptake were 1.5-fold higher in SKOV3 tumours than MDA-MB-231 cells, and no significant differences were observed between the HER2 aptamers and the negative control, suggesting tumour uptake was due to tumour factors other than HER2 expression [124].