CD22 and neoplasm: Resistance to CAR-T-cell therapies occurs in most human patients by the loss or downregulation of CD19 and/or CD22 on malignant B cells, leading to “antigen escape”, or the expression of inhibitory ligands, such as programmed cell death 1 ligand 1 (PDL1), impaired apoptosis, and an immunosuppressive tumor microenvironment [66].