Because of a lack of specificity and short half-life, other serine protease inhibitors, such as factor D, were not transferred to clinical trials, and further development was stopped (145, 146) . sCR1/TP10 is a soluble complement regulator inhibiting both the classical and alternative pathways and therefore is rather promising regarding ischemia/ reperfusion injury and various other conditions. The substance revealed some protective effects in male patients undergoing coronary artery bypass grafting but not in females (145, 147) . Therefore, clinical trials have been stopped (145) . Similar substances such as sCR1-sLe x / TP20 with an improved structure (148) and Microcept/APT070 (149) are currently under investigation for the treatment of diseases such as acute myocardial infarction, stroke and inflammatory diseases but have not entered clinical evaluation (150) .