TNFRSF17 and plasma cell myeloma: Belantamab mafodotin is the first‐in‐class antibody‐drug conjugates (ADC) targeting B‐cell maturation antigen (BCMA) approved for relapsed/refractory multiple myeloma (RRMM) who received at least four prior LOTs including a PI, an IMiD, and an anti‐CD38 mAb.