FTL and idiopathic pulmonary fibrosis: To investigate the mechanisms underlying FTL elevation in PS-NPs-induced lung fibrosis, we first analyzed single-cell transcriptomes from the Human Lung Cell Atlas (HLCA) and found that FTL expression is significantly increased in alveolar epithelial cells of early-stage IPF patients (Fig. 4A; data from Sikkema et al., [34].