PROCR and systemic mastocytosis: Both the group A and DC8 subsets of EPCR binding var genes were predictive of pediatric SM (group A: DBLα not var3; DC8: DBLβ12 and DBLβ3/5, DBLα-CIDRα, and CIDRα1.1; and DC8-group A: DBLα2/α1.1/2/4/7).