First, using the chemotherapeutic drug GEM to investigate the functional impact of proliferating Ly6Chi and Ly6G+ myeloid cells in EAE, as well as in OM-MOG tolerance, we show that depletion of peripheral Ly6Chi and Ly6G+ cells by GEM administration prior to disease onset temporarily delays the development of EAE. The gene discussed is MOG; the disease is ocular melanoma.