Lastly, several cytokines involved in TH2 cell recruitment and fibrosis (IL-6, eotaxin, PDGF-ββ, IL-10, IL-1β) were released from macrophages in vitro and correlated with in vivo BAL response, which aligns with KE4 (TH2 cell activation) in the lung fibrosis AOP. This evidence concerns the gene IL1B and pulmonary fibrosis.