IHC analysis on serial sections from normal (Supplemental Figure 3, A, B, E, F, I, J M, and N) and IPF (Supplemental Figure 3, C, D, G, H, K, L, O, and P) lung explants showed that CCL28+ cells were diffusely localized in normal lungs (Supplemental Figure 3, A and B) and localized in focal regions in IPF lung tissues (Supplemental Figure 3, C and D). Here, CCL28 is linked to idiopathic pulmonary fibrosis.