NOTCH4 and pulmonary fibrosis: We also found expression of genes associated with Notch signaling such as NOTCH4, which contains SSc-associated polymorphisms, and with the epithelial-mesenchymal transition (EMT) such as LATS2. Alternatively activated macrophages are known to produce large quantities of TGFβ in SSc pulmonary fibrosis [29], suggesting that the M2 macrophage subnetwork could drive activation of the TGFβ/ECM subnetwork.