This agent is of particular interest because macrolides have an established role in treating aseptic inflammatory conditions, including chronic rhinosinusitis (Oakley et al., 2017) and panbronchiolitis (Lin et al., 2015), and because CLA has previously been trialled in IBD with divergent outcomes (Leiper et al., 2008, 2000). This evidence concerns the gene SELPLG and chronic rhinosinusitis.