Subsequently, we used DO-11.10 murine CD4 cells [a T cell hybridoma specific for chicken ovalbumin (OVA), a gift from P. Marrack, National Jewish, Denver, CO, and J. Maynard, UT Austin, Austin, TX] to test the ability of IRF8 WT or KO lymphoma cells to present antigen and, in the context of MHCII, activate CD4 T cells. The gene discussed is CD4; the disease is lymphoma.