TACSTD2 and endometrial cancer: To evaluate the ability of Dato-DXd to induce a bystander killing effect against endometrial cancer with heterogeneous TROP2 expression, we tested the ADC activity by admixing END(K)265 cells (i.e., 3+ TROP2 expression) with negative TROP2-expressing cells [i.e., END(K)34] for 48 hours.