TNF and myeloproliferative disorder: Likewise, smoking triggers systemic inflammation by releasing and activating acute phase proteins and pro-inflammatory cytokines; thus an additive effect of MPN and smoking seems plausible as many of the elevated inflammatory markers (CRP, IL-1β, IL-6, IL-8, TNFα, GM-CSF and MCP-1) are overlapping [4, 5, 8–10, 18, 27, 34].