COL18A1 and pulmonary arterial hypertension: Amongst them, a missense variant in the collagen type XVIII alpha 1 chain (COL18A1) gene (rs62000962, V661I, MAF = 0.11, classified as benign in ClinVar) and another missense variant in the mitochondrial elongation factor 2 gene (MIEF2)—also known as SMCR7 (rs12603700, G324E, MAF 0.12, not reported in ClinVar)—have been first putatively associated with PAH [114,115] and recently identified in patients with cPC-PH.