TGFB1 and idiopathic pulmonary fibrosis: Following 6 weeks of culture with TGFβ1 in the absence (control) or presence of IOX2 to drive HIF pathway activation, mature pyridinoline cross links (DPD/PYD) were significantly increased by the addition of IOX2 (Figure 5a) and these achieved a level comparable to our previous findings in IPF tissue (Jones et al., 2018).