IL15 and myeloid sarcoma: We observed that the CSF of both progressive forms of MS contains detectable levels of five cytokines, namely IL-1ra, IL-9, IL-15, TNF-α, and IFN-γ, seven chemokines, namely IL-8, IP-10, MCP-1, MIP-1α, MIP-1 β, RANTES, eotaxin, and the growth factor, VEGF (Figure 1).