Röhrich et al. aimed to evaluate the imaging properties of 68Ga-FAPI PET/CT in PF and to confirm FAP expression in fibrotic lesions via biopsy and immunohistochemistry of human samples and in lung sections of genetically engineered mice with an idiopathic pulmonary fibrosis (IPF)-like lung disease. Here, FAP is linked to idiopathic pulmonary fibrosis.