PDCD1 and plasma cell myeloma: Particularly, in the 2020s, four mAbs were approved by the FDA (Table 1) [18]: (i) isatuximab (Sarclisa®) against CD38 for multiple myeloma in 2020, (ii) tafasitamab (Monjuvi®) against CD19 for diffuse large B cell lymphoma in 2020, (iii) naxitamab (Danyelza®) against GD2 for high-risk neuroblastoma and refractory osteomedullary disease in 2020, and (iv) dostarlimab (Jemperli®) against PD-1 for endometrial cancer in 2021.