| PPI | Pre-pulse inhibition |
|---|---|
| PPI | Present Pain Intensity |
| PPI | Proton Pump Inhibitor |
| PPI | Purified Pork Insulin |
| PPi | Pyrophosphate |
| PPi-PFK | Pyrophosphate-dependent phosphofructokinase |
| PPIase | Peptidyl-prolyl cisltrans isomerase |
| PPIases | Peptidyl-prolyl isomerases |
| PPIC | plasmin plasmin inhibitor complex |
| PPII | poly(L-proline) II |