| 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... |
| PRF | partial reinforcement; patient report form; perforin; plasma recognition factor; pontine reticular f... |
| PSF | peak scatter factor; peptide supply factor; point spread function; pseudosarcomatous fasciitis |