FOXP3 and myeloid sarcoma: Although Foxp3+ Treg have low levels of CD49d (i.e., the alpha-4 chain of VLA-4), treatment with the monoclonal antibody natalizumab blocks the transmigration of FoxP3+ Treg in a similar manner to FoxP3−CD4+ nonregulatory T cells isolated from the peripheral blood of MS patients [124].