In peripheral blood mononuclear cells (PBMC) from MS patients, stimulation with phycocyanin induced a regulatory T cell (Treg) response, by increasing the expression of all Treg cell markers, including CD25, Foxp3, TGF-β, and IL-10, and the number of CD4+CD25highFoxp3+ T cells, indicating an ability to induce the Treg subset, which is reduced in MS patients [112]. The gene discussed is CD4; the disease is myeloid sarcoma.