Hemophilia, where clotting factors that are required to stop bleeding are not present in a sufficient quantity, has been a prime target.[15, 190, 191] In one example, an LNP platform was used to deliver human factor IX mRNA for the treatment of hemophilia B.[15] After repeated dosing into mice, higher circulating factor IX concentrations, along with higher clotting activity, were achieved. The gene discussed is F9; the disease is hemophilia B.