CD19 and B-cell chronic lymphocytic leukemia: Chronic lymphocytic leukemia and B-cell non-Hodgkin lymphoma had the lowest seroconversion percentages and antibody levels, consistent with other studies.7 Noteworthy was the complete lack of an antibody response in patients treated with anti-CD20 monoclonal antibodies and low seroconversion percentages among those treated with BTK inhibitors, venetoclax, and CD19-CAR-T.