CD33 and neoplasm: These findings warrant further investigation in an autologous setting and in various other model systems into how much tumor reduction has occured immediately after the brief drug treatment; the ratio of E:T in the blood, bone marrow, and spleen within 24h of the last dose; and whether these redirected T cells would respond in vitro to tumor cells both with and without the CD33 antigen to which the bispecific was directed.