The discrepancy in controls’ levels versus IPAH patients with regard to ADAMTS13, could thus be ascribed to the different sampling time in relation to the PAH diagnosis, as we sampled during the diagnostic RHC and their sampling delay from the diagnosis of IPAH was not reported quantitively.31 Moreover, the inconsistency could also be attributed to a putative effect of treatment response. This evidence concerns the gene ADAMTS13 and idiopathic pulmonary arterial hypertension.