Viral induction of TGFB1 predicts profibrotic signaling to most epithelial cells and fibroblasts expressing both TGFBR1 and TGFBR2 (Fig. 4 g), including myofibroblasts, which constitute the fibroblast foci in lung fibrosis. Here, TGFB1 is linked to pulmonary fibrosis.