No significant differences in gene expression of MMP8, 16 other matrix metalloproteases, CD28, ICOS, LCK, ITK, or 44 other genes of a 52-gene expression signature associated with outcome in idiopathic pulmonary fibrosis were found (Tables S2 and S3 in Supplementary Material). Here, CD28 is linked to idiopathic pulmonary fibrosis.