TACSTD2 and neoplasm: In another series of Trop2-specific nanobody tracers (68Ga-NOTA-RTD98, 68Ga-NOTA-RTD161, 68Ga-NOTA-RTD01, and 68Ga-NOTA-T4) that were recently developed by Huang et al. (18, 19), 68Ga-MY6349 demonstrated the lowest liver uptake and a favorable tumor-to-liver ratio in mice bearing BxPC-3 tumors.