| OAF | open air factor; osteoclast activating factor |
|---|---|
| OGF | ovarian growth factor; oxygen gain factor |
| OSF | organ system failure; osteoclast-stimulating factor; outer spiral fiber; overgrowth stimulating fact... |
| OTF | octamer-binding transcription factor; oral transfer factor |
| PPF | pellagra preventive factor; phagocytosis promoting factor; phosphonoformate; plasma protein fraction... |