Four other ADCs that contain this promising linker-payload are currently under clinical evaluation for the treatment of solid tumors, by targeting either HER3 in NSCLC, metastatic colorectal and breast cancers, TROP2 in NSCLC and triple negative breast cancer (TNBC), B7-H3 in advanced solid tumors or GPR20 in gastrointestinal stromal tumors (GIST) (Table 1). The gene discussed is GPR20; the disease is gastrointestinal stromal tumor.