CD8A and neoplasm: Tumor-associated FOXP3+ cell infiltration is reduced in Ndst1f/f CD11cCre+ mutant mice. A basal or background level of CD8+ and FOXP3+ cells (consistent with Treg cells) exists in the lung interstitium, with comparable densities (stained cells per HPF) for each cell type in mutant versus wildtype tumor-bearing lungs (Fig. 2A).