TNF and chronic obstructive pulmonary disease: Although TNF-α has been linked with physiologic proliferation and differentiation of B cells under steady-state conditions, elevated levels have been linked with a wide variety of diseases including COPD and amplify inflammation through the activation of cells’ nuclear factor kappa-light-chain-enhancer of activated B (NF-kB), activator protein 1 (AP-1), and other transcription factors [10].