To ensure comparability with clinical CD4/CD8 T cell ratios, we extracted the number of CD4‐expressing and CD8‐expressing T cells from the IPF pbmc single‐cell Seurat object and SSc‐ILD lung Seurat object to calculate the CD4/CD8 ratio (Supplementary File 1). This evidence concerns the gene CD4 and idiopathic pulmonary fibrosis.