IFNG and chronic obstructive pulmonary disease: However, Freeman et al. reported that Tc (CD8+) cells from COPD patients have increased expression of TLR1, TLR2, TLR4, TLR6, and TLR2/1 as well as Tc1 cytokines (IFN-γ and TNF-α) compared to healthy individuals that may imply the auto-aggressive response of lung Tc cells in COPD lung inflammation (299).