High concentrations of MIP-1α, granulocyte-macrophage colony-stimulating factor (GM-CSF), and macrophage colony-stimulating factor (M-CSF) were found in macrophages in patients with mild HPS1 pulmonary fibrosis [109], and these inflammatory factors may be the pathogenic cause of early HPS1 pulmonary fibrosis. This evidence concerns the gene CSF2 and pulmonary fibrosis.