COL18A1 and systemic sclerosis: Proteomic screening of 313 proteins was performed, and random forest analysis identified a novel panel of eight proteins (collagen IV, endostatin, insulin-like growth factor binding protein 2, insulin-like growth factor binding protein 7, matrix metallopeptidase-2, neuropilin-1, NT-proBNP and receptor for advanced glycation end products) which discriminated PAH from non-PH SSc patients from the DETECT Cohort [63].