CD19 and diffuse large B-cell lymphoma: However, most recently, the CD19 antibody tafasitamab (formerly MOR208 or Xmab®5574), which was optimized by engineering its fragment crystalizable (Fc) domain to overcome limitations of native CD19 antibodies, has demonstrated clinical efficacy and has received approval by the FDA for combination treatment with the immunomodulatory drug lenalidomide in diffuse large B cell lymphoma (DLBCL) patients [7,8].