CD22 and neoplasm: This IT is probably the most effective at inhibiting protein synthesis in various CD22+ target cell lines (Daudi, EHM, BJAB, Raji and BM21), with IC50s ranging from <5 × 10−15 (on EHM cells) to 2 × 10−11, and IC90s ranging from 5 × 10−14 to 10−10 M. Treatment with the IT (0.5 mg/kg at days +1, +4 and +7 after tumor challenge) was found to significantly extend the survival time of SCID mice bearing transplanted Daudi cells, with 33% of all animals tumor-free after 220 days.