KIT and chronic obstructive pulmonary disease: We identified 4 c-Kit+ cell populations, with similar proportions in NS, S and COPD: (1) By FACS, c-Kithigh/CD45+ cells (4.03 ± 2.97% (NS), 3.96 ± 5.30% (S), and 5.20 ± 3.44% (COPD)).