IGFBP7 and idiopathic pulmonary fibrosis: Furthermore, genetic susceptibility for IPF and COVID-19 seem to be similar, as confirmed by the fibrotic plasma biomarkers such as thrombospondin 2 (TSP2), glial-derived factor 15 (GDF15), insulin-like growth factor binding protein 7 (IGFBP7), and procollagen type III (PROC3) (Ackermann et al. 2022).