Clinical studies focusing on primary and secondary hemostasis during hantavirus disease showed thrombocytopenia in both HFRS and HCPS, a decreased plasma activity of coagulation factors II, V, VIII, IX, and X in acute HFRS patients, prolongation of the prothrombin and activated partial thromboplastin time, increased thrombin generation and D-dimer levels and a decrease in ADAMTS13 activity in acute PUUV patients (Lee, 1987; Mackow and Gavrilovskaya, 2009; Laine et al., 2011; Mustonen et al., 2013). The gene discussed is F2; the disease is Thrombocytopenia.