Interestingly, angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2, has also been shown to be upregulated in lung fibroblasts from models of chronic, but not acute, lung inflammation, suggesting a direct contribution of lung fibroblasts to infection susceptibility in patients with COPD and IPF (75, 76). Here, ACE2 is linked to infection.