The total leukocyte numbers (CD45+ cells) in lung parenchyma were similar in early and end-stage IPF [390.5 (216–733) vs. 380 (149–789) cells/mm2] but higher than in smoking controls [112 (37–237); p < 0.0001 for both; Table 2]. The gene discussed is PTPRC; the disease is idiopathic pulmonary fibrosis.