These molecules may be expressed by primary or metastatic tumor cells or by various cells such as T cells, CD4 T cells, Th17 Cells, CD4 Treg cells, CD8 T cells, CD8 Treg cells, NK T cells, γ∞T cells, B cells, dendritic cells, monocytes/macrophages, or neutrophils, which are present in the environment under physiological and pathological conditions. The gene discussed is CD4; the disease is neoplasm.