CD19 and precursor B-cell acute lymphoblastic leukemia: Regarding biologics and cell therapies, they have been used since 1997 with rituximab, a monoclonal antibody targeting the antigen CD20 in lymphoma B cells [7], and since 2017 with tisagenlecleucel, a CD19-directed genetically modified autologous CAR T-cell therapy indicated for the treatment of B-cell precursor acute lymphoblastic leukemia (ALL) [8].