Since we had previously observed significant increases in tumor-infiltrating T lymphocytes in mice carrying the 4T1/Ubr5−/− tumor [6], it was of interest to note that both CD4+ and CD8+ T cells were markedly decreased in spleens in the 4T1/Ubr5−/− shCdc73 tumor-bearing mice (Fig. 3D, E), and intratumoral CD8+ T cells were also strongly inhibited (Fig. 3F), whereas CD4+ T cells were not affected (Fig. 3G). This evidence concerns the gene CD4 and neoplasm.