With the aim of evaluating the relevance of IL-33 among interstitial lung diseases, Lee et al. [49] conducted a study among idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases, including non-specific interstitial pneumonia (NSIP), hypersensitivity pneumonitis (HP), and sarcoidosis, concluding that IL-33 levels detected in bronchoalveolar lavage fluids may be useful in differentiating IPF from other chronic interstitial lung diseases (ILDs). The gene discussed is IL33; the disease is pulmonary fibrosis.