CTLA4 and neoplasm: The full CRI regimen combining all four components, RT, srIL-2, IL-12, and anti-CTLA-4 induced rapid (within 3-4 weeks) complete regression of most tumors (4 of 5) in this group; the only tumor that did not regress was one that had a size of ~2600 mm3 when the treatment started, although a separate tumor of a similar size still responded to that treatment (Figures 1B, C).