In ILD, CD8+ T cells are known to diffusely infiltrate the parenchyma of fibrotic IPF tissues and can differentiate into subtypes that either produce IFN‐γ but not IL‐4 (which may mitigate fibrosis) or IL‐4 but not IFN‐γ (which could promote fibrosis) [15]. The gene discussed is CD8A; the disease is idiopathic pulmonary fibrosis.