IFNG and chronic obstructive pulmonary disease: In addition, the synergistic action of TNFα with IFNγ to increase expression and release of CXCR3 chemokines has been reported previously [14, 15, 21] and since TNFα is also elevated in the airways of patients with COPD [22], the effects of JAK inhibition on this stimulus was also evaluated and showed similar attenuation of chemokine output.