Activation of TGF‐β by the αVβ6 integrin is likely to be a central driver of lung fibrosis, but measurement of αVβ6 integrin‐mediated TGF‐β activation is especially challenging because it does not lead to free release of measurable amounts of active TGF‐β. The gene discussed is TGFB1; the disease is pulmonary fibrosis.