c1F6 prolongs survival of SCID mice bearing B-lymphoma xenografts. (A) Beginning one day after intravenous challenge with Raji cells, mice were given 4 doses of c1F6 at 4 mg/kg or 1 mg/kg once every 4 days as indicated by the inverted triangles. Control mice were untreated or treated with nonbinding IgG1 according to the same schedule. (B) Survival of mice bearing disseminated Raji or IM-9 lymphoma after treatment with a single 4-mg/kg dose of c1F6 administered 1 or 5 days after tumor cell injection (n = 10 per group). P values given are between c1F6-treated groups and either control IgG–treated or untreated group.