The IL-17 signalling pathway was also enriched in M1 macrophages, which is notable because NLRP3 inflammasome activation and IL-1β release have been linked to enhanced inflammatory Th17 cell responses in diseases including ankylosing spondylitis [40], inflammatory skin diseases including hidradenitis suppurativa [41, 42], rheumatoid arthritis [43] and obliterative bronchiolitis [44]. Here, NLRP3 is linked to bronchiolitis obliterans syndrome.