The question is whether ADAMTS13 could be considered a reliable biomarker for the diagnosis of TTP, since there are several studies supporting a statistically significant decrease in ADAMTS13 in other TMAs, such as HELLP syndrome/preeclampsia [2,17,18,19,20,21,22,24]. The gene discussed is ADAMTS13; the disease is thrombotic thrombocytopenic purpura.