Despite only modest changes in the percentage of T cells, the absolute number of T cells was significantly altered in the absence of myeloid Setdb2. Notably, Setdb2ffLyz2Cre+ mice had 3 times the number of both CD4+ T cells (5.81 ± 0.50 x 105 vs. 15.43 ± 0.84 x 105; p<0.001) and CD8+ T cells (3.82 ± 0.37 x 105 vs. 9.69 ± 0.59 x 105; p<0.001) in the lungs on day 6 post-infection. This evidence concerns the gene CD4 and infection.