CD4 and idiopathic pulmonary fibrosis: While we were unable to obtain blood from our controls, the IPF patient’s blood had significantly greater CD4+ T cells (35.95%; range, 24.70–44.20%) than CD8+ T cells (19.99%; range, 10.50–33.10%; p = 0.002), and a CD4:CD8 ratio of 2.15 (range, 0.81–3.58).