To investigate the appropriate concentration and stimulation time of TGF-β1 in inducing CF transformation into myofibroblasts, we first measured the effects of several concentrations of TGF-β1 on inducing α-SMA protein expression after 48 h of incubation, which is the hallmark of myofibroblasts (44–46). Here, TGFB1 is linked to cystic fibrosis.