(In fact, while CD8+ T cells had comparable densities (∼ 4.5 cells/HPF) in the background lung among genotypes, as in Fig. 2A, counting of specific tumor-associated CD8+ T cell densities (1.3/HPF for mutants and 3.1/HPF for wildtype) identified even lower densities than that of background lung). The gene discussed is CD8A; the disease is neoplasm.