STAT3 and pulmonary fibrosis: A previous study in vivo also showed induction of STAT3-mediated Gremlin-1 in lung fibrosis (Wong et al., 2014) and a recent paper demonstrated that IL-6 trans signaling in idiopathic pulmonary fibroblasts elevated Gremlin-1, which was reduced with tocilizumab (Epstein Shochet et al., 2020).