The correlation between subpopulations of PS (+) erythrocytes and the risk of stroke in patients with SCD has also been demonstrated.71 Overall, the role of RBC in the coagulation activation has been shown that includes a significant correlation between the numbers of RBCs with external exposure of phosphatidylserine with plasma markers of thrombin generation, such as prothrombin fragment 1+2 (F1+2), D-dimer and plasmin- antiplasmin complexes. The gene discussed is F2; the disease is Schnyder corneal dystrophy.