TGFB1 and idiopathic pulmonary fibrosis: However, concentrations of P-Selectin significantly correlated with increasing concentrations of MMP7 in the plasma of patients with IPF (Fig. 2I) to suggest that activated platelets may contribute to IPF disease, although levels of platelet-derived mediators such as TGFβ1 did not correlate with P-Selectin levels (Fig. 2, J and K).