SYK and stroke disorder: However, other activation pathways involved in macrophage polarization in the brain after stroke are also described that include toll-like receptor (TLR)-4/TNF receptor-associated factor (TRAF)-6 pathway, TLR3/interferon regulatory factor (IRF)-3 pathway, or spleen tyrosine kinase (SYK) signaling through either CD8, FcγR or Clec4 receptors [18–20].