Idiopathic pulmonary (lung) fibrosis (IPF) affects 5 million people with a mean survival time of 2-3 years after diagnosis. In lung fibrosis, connective tissue fibroblasts excessively produce and stiffen collagen matrix. The resulting scar destroys the delicate lung architecture, decreases lung compliance and gas exchange, ultimately rendering patients unable to breathe. The only effective treatment for IPF patients is a lung transplant. Typical of lung fibrosis is the chronic co-existence of fibroblasts, innate immune macrophages, and adaptive immune T-cells.