Earlier studies of sentinel lymph nodes, based on PCR or immunohistochemical (IHC) analysis, identified increased gene expression level of FOXP3, indicative of increased level of regulatory T cells (Tregs), and reduced frequency of CD4 T cells and mature dendritic cells in nodes with metastasis as compared to nodes without tumor cells [18, 19, 20]. The gene discussed is CD4; the disease is neoplasm.