TACSTD2 and neoplasm: With [68Ga]Ga-NOTA-T4 immunoPET readily available for clinical use, we can noninvasively detect Trop2 expression to assist in clinical decision-making in terms of patient stratification (select Trop2-positive patients for treatment and prevent futile treatment of Trop2-negative patients) and response monitoring (assess the response of tumours and off-tumour on-target toxicity).