CD4 and neoplasm: GR9-A7 tumor-bearing mice also showed a slight decrease in several immune cell subsets, with a reduction in TCD3+ lymphocytes vs. wild-type animals (30.3 vs. 33.1%) due to a decrease in TCD8+ (5.8 vs. 6.9%) and TCD4+ (24.4 and 26.1%) subpopulations; while a significant increase in Treg cells was observed (10.8 vs. 4.4% of CD4+).