Pirfenidone and tranilast, through unclear mechanisms (Aimo et al, 2020), both reduce the expression and secretion of TGFβ in CF in vitro and subsequently reduce myofibroblast transformation in response to profibrotic stimulation (Martin et al, 2005; Shi et al, 2011). Here, TGFB1 is linked to cystic fibrosis.