IL1RL1 and pulmonary fibrosis: USP38 interacts with IL-33R to deregulate the polyubiquitination of its K27 linkage at K511, whereas the E3 ubiquitin ligase tumor necrosis factor receptor-related factor 6 (TRAF6) catalyzes the polyubiquitination of IL-33R here, and together they regulate IL-33R levels and signaling, which in turn modulates the local inflammatory response to lung fibrosis 86.