Previous research has shown that the three isoforms of transforming growth factor β (TGF-β) have distinct cellular expression patterns, with TGF-β2 and TGF-β3 expression being specifically elevated in human fibrotic lung and liver tissue. Since pan-TGF-β inhibition had proven to be toxic for chronic use, in recent work, researchers from Genentech Inc. aimed to assess whether specifically targeting one of the TGF-β isoforms could represent a novel therapeutic option for patients with chronic fibrotic disorders.