However, the severity of pulmonary disease in HPS2 patients appears to have no significant correlation with levels of MIP-1α, MCP-1, interferon-gamma (IFN-γ), regulated-upon-activation normal T cell expressed and secreted (RANTES), GM-CSF, platelet-derived growth factor BB (PDGF-BB), matrix metalloproteinase-1 (MMP-1), and matrix metalloproteinase-7 (MMP-7) [42]. This evidence concerns the gene MMP1 and lung disorder.