In addition to confirming that CTLA4 is primarily expressed in T cell subpopulations, a search of larger single-cell RNA transcriptomic datasets of human IPF (IPF Cell Atlas; https://www.ipfcellatlas.com/) served to validate our original digital spatial observation that CTLA4 is upregulated in IPF lungs. This evidence concerns the gene CTLA4 and idiopathic pulmonary fibrosis.