SYN3 and myeloid sarcoma: Th2 cytokines downregulated the genes for synapsin 3, a synaptic vesicular protein inhibited by Ca2+ [198], as well as semaphorin 3a; downregulation of this protein in MS or other diseases by cytokines would have major implications for pathogenesis and repair since semaphorin 3 inhibits growth cones as a chemorepellant and may be an important inhibitor of axonal regeneration and outgrowth.