CD4 and idiopathic pulmonary fibrosis: Data showed that IPF (SN) increased the expression of tmTNF on CD4+ and CD8+ T cells at 3 h (mean 11% and 2%, respectively) compared with CD4+ and CD8+ T cells in media (mean 1.8% and 0.3%, respectively), and the CD4+tmTNF+ was maintained even at 24 h of culture (mean 5%).