For this purpose, nude mice were engrafted subcutaneously with CLBL-1 cells and injected 2 weeks after engraftment with each of the four MAbs radiolabeled with 125I. Even if the activity to the tumor remains rather low, these results are consistent with what is described in the literature after injection of anti-CD22 MAb hLL2 in nude mice bearing human lymphoma xenografts (28). The gene discussed is CD22; the disease is neoplasm.