CD22 and acute lymphoblastic leukemia: The FDA has just approved inotuzumab ozogamicin (Besponsa®) (Pfizer Inc. and UCB S.A.)anti-CD22 ADC therapy in patients with acute lymphoblastic leukemia [52], which combines the epratuzumab anti-CD22 mAb with the cytotoxic antitumor antibiotic calicheamicin (Figure 6).