CTLA4 and pulmonary fibrosis: To determine if the finding of upregulated expression of CTLA4 was more broadly applicable to human lung fibrotic disorders, we queried a publicly available single-cell RNA-Seq (scRNA-Seq) dataset (IPF Cell Atlas; https://www.ipfcellatlas.com/); this confirmed that CTLA4 is highly expressed in pulmonary fibrosis, preferentially within the T cell population, in a cohort of 20 patients with pulmonary fibrosis, including 12 with IPF and 10 individuals acting as controls, representing 114,396 total cells (Figure 2, E–G).