A method of screening a test compound, e.g., a fibrosis or IPF inhibitor, for induction of an unjammed-to-jammed transition (UJT) in fibrotic primary human bronchial epithelial cells (HBECs) isolated from a subject with a fibrotic lung disease includes culturing the fibrotic primary HBECs at an air-liquid interface for a time sufficient to provide a differentiated pseudostratified epithelium contacting the cultured cells with the test compound; and monitoring the motility of the cultured cells to identify the cultured cells as moving or stationary; wherein stationary cultured cells indicate that the test compound induces the UJT. Also included are methods of identifying lung fibrosis biomarkers.