The most abundant cell type in lung interstitium is fibroblasts. They resemble ordinary fibroblasts but have some distinguishing features, such as long branching processes and gap junctions. HPF main function is to produce type III collagen, elastin, and proteoglycans of the extracellular matrix of the alveolar septa. Human Pulmonary fibroblasts (HPF) play an important role in the repair and remodeling processes following injury. The controlled accumulation of fibroblasts to sites of inflammation is crucial for effective tissue repair after injury . Either inadequate or excessive accumulation of fibroblasts can result in abnormal tissue function. For example, the excess proliferation of fibroblasts contributes to the adventitial thickening observed during the development of hypoxia-induced pulmonary hypertension.