TGFB1 and pulmonary fibrosis: Alveolar macrophages are key players in the initiation and resolution of inflammation (Pound & Ritskes‐Hoitinga, 2018), a major source of TGF‐β (Szegedy et al., 2016), and capable of exacerbating pulmonary fibrosis by stimulating fibroblast proliferation and collagen synthesis (Chollet et al., 2015; Kingma & Ba, 2015).