The number of PAFR negative alveolar macrophages is significantly higher in NC (median 72,072 cells per mm2, range 42,026–169,141 cells per mm2) compared to IPF (median 8048 cells per mm2, range 0–71,342 cells per mm2, p = 0.0005) (Figure 3D). The gene discussed is PTAFR; the disease is idiopathic pulmonary fibrosis.