Fibroblast growth factor 1 (FGF1) is also linked to PPAR-γ: Mackenzie et al. reported it to be the growth factor most significantly increased in IPF patients, and that it co-localized in basal cell sheets, myofibroblast foci and surfactant protein-C positive alveolar epithelial type-II cells, and with FGFR1, FGFR2, FGFR3, FGFR4 and myofibroblasts [81]. The gene discussed is PPARG; the disease is idiopathic pulmonary fibrosis.