TACSTD2 and neoplasm: Off-tumour on-target toxicity could be predicted not only by observing the radioactivity uptake of [68Ga]Ga-NOTA-T4 in the subject’s organs but also by noninvasively visualising the pharmacokinetics and pharmacodynamics of mAbs and ADCs labelled with long half-life radionuclides (89Zr, 64Cu, etc.), as a way of minimising the risk of possible off-tumour toxicity in normal tissues/organs expressing Trop2.