USP13 and idiopathic pulmonary fibrosis: Strangely, differing from the downregulation of USP13 in IPF lungs, USP13 was markedly increased in fibroblasts isolated from mice challenged with bleomycin (BLM) and in TGF-β1-treated lung fibroblasts, accompanied by the increased expression of FN and collagen (Liao et al., 2020).