Factor IX yakawanikwa muna 1952 mumurwere wechidiki ane hemophilia B anonzi Stephen Christmas (1947<unk>1993). Kushomeka kwake kwakatsanangurwa naDr. Rosemary Biggs naPurofesa R.G. MacFarlane muOxford, UK. Chinhu ichi, saka, chinonzi Christmas Factor. Christmas aigara muCanada, uye akaita mushandirapamwe wekuchengetedzwa kwekuwedzerwa kweropa kusvika pakufa kweAIDS yakabatana nekuwedzerwa ropa pazera remakore makumi mana nematanhatu. Rimwe zita rechinhu ichi iplasma thromboplastin, rakapihwa neboka rakazvimirira muCalifornia.
Chinhu cheKrisimasi