IFNG and coronary artery disorder: Corresponding to the elevated Th1 cells, more IFNγ producing CD4+ cells were observed in heavy smokers compared to all other groups (9.7 ± 9.1% for HS vs. 3.7 ± 3.8% for YH, 2.7 ± 3.4% for EH, 3.4 ± 4.0% for YS and 2.9 ± 4.1% for CAD).