IL1RL1 and interstitial lung disease: Of the 41 transcripts that were synergistically upregulated by the combination of LIGHT with IL-13 (Fig. 3), some, such as CCL2, CH25H, IL1RL1, EGR2, RGS4, and IL32, were strongly expressed in ILD fibroblast clusters 11 or 12, whereas others were randomly expressed in alternate clusters (Fig. S2A).