Factor IX yakawanikwa muna 1952 mumurwere wechidiki ane hemophilia B anonzi Stephen Christmas (1947<unk>1993). Kushomeka kwake kwakatsanangurwa naDkt. Rosemary Biggs naPurofesa R.G. MacFarlane muOxford, UK. Chinhu ichi, saka, chinonzi Krisimasi Factor. Krisimasi yaigara muCanada, uye yakashandira kuchengetedzwa kweropa kusvikira yafa neAIDS-yakabatana nekuwedzerwa ropa pazera remakore makumi mana nematanhatu. Rimwe zita rechinhu ichi iplasma thromboplastin, rakapihwa neboka rakazvimirira muCalifornia.
kufa neAIDS inokonzerwa nokuisirwa ropa