Split-well assay for cytotoxic lymphocytes. (A) Plot showing % lysis prior to vaccination in each of 24 wells containing T2 cells alone (open) or pulsed with Melan-A peptide (filled). (B) Plot showing % lysis on day 57 after completing vaccination and administration of IL-12. The subject received rhIL-12 i.v. at a dose of 30 ng/kg.