Given the notion that a fruitful antitumor response requires the effective presentation of tumor antigens via MHC-II by APCs to CD4 T lymphocytes [22], we evaluated whether the decreased expression of MHC-II molecules in monocyte-derived macrophages exposed to tumor cells or the tumor D-ECM impacts on their ability to present antigens to T cells, affecting the proliferation rate. The gene discussed is CD4; the disease is neoplasm.