Flow cytometric analysis of CD45+ and CD45– cells from IPF lung explants and control lungs revealed that within the CD45+ immune cells few CD68+ cells expressed CCR10 (Supplemental Figure 1, A and B; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.141061DS1), but there was a significant increase in the percentage of CCR10-expressing CD3+CD4+ helper T cells (Supplemental Figure 1, C and D), CD3+CD8+ cytotoxic T cells (Supplemental Figure 1, C and E), and CD19+ B cells (Supplemental Figure 1, F and G) from IPF lungs compared with normal lungs. This evidence concerns the gene CD8A and idiopathic pulmonary fibrosis.