In a pulmonary fibrosis mouse model, mannosylated LNPs encapsulating G2 and S phase expressed protein 1 (GTSE1) siRNA significantly decreased collagen accumulation and down-regulated the epithelial-mesenchymal transition (EMT) associated-protein in the lungs, leading to functional recovery from pulmonary fibrosis. Here, GTSE1 is linked to pulmonary fibrosis.