IGFBP5 and idiopathic pulmonary fibrosis: IGFBP5 (insulin‐like growth factor‐binding protein 5) is also one of the substantially upregulated genes in D (82‐fold, compared to N), and it has been observed to be upregulated in the fibrotic disorders systemic sclerosis/scleroderma and idiopathic pulmonary fibrosis.