CD4 and neoplasm: To investigate whether chronic restraint stress could influence immune cell populations in the ovarian tumor microenvironment, we examined F4/80+ macrophages and CD4+ and CD8+ T-cell subtypes using immunohistochemistry (IHC) on paraffin-embedded tumor samples from ID8Luc and IG10Luc tumor-bearing mice that underwent daily restraint stress versus control for four weeks.