Ueno et al. (2011) highlighted a crucial role of HIF-1α in mediating the effects of TGF-β1 on PAI-1 expression during bleomycin-induced pulmonary fibrosis. We found that after irradiation or Yoda one exposure, the Ca2+ concentration increased, expression of HIF-1α increased, and expression of TGF-β1 increased. PIEZO1 specific siRNA attenuated the Ca2+ influx, HIF-1α accumulation as well as TGF-β1 expression caused by irradiation. The gene discussed is PIEZO1; the disease is pulmonary fibrosis.