Currently MB-CART2019.1 is being tested in one multicenter phase I/II dose-finding trial in Germany with up to 12 adult patients suffering from r/r, aggressive CD19- and CD20-positive B-NHL/CLL or B-cell small lymphocytic lymphoma (B-SLL) (NCT03870945). The gene discussed is CD19; the disease is B-cell chronic lymphocytic leukemia.