Herein, we discovered a critical role of RCN3 in orchestrating fibroblast function during pulmonary fibrosis, as evidenced by key findings: (1) RCN3 was notably upregulated in fibroblasts from both patient and mouse fibrotic lungs, whereas RCN3 knockdown diminished activation of lung fibroblast from IPF patients. The gene discussed is RCN3; the disease is pulmonary fibrosis.