| OCN | oculomotor nucleus; oncology certified nurse |
|---|---|
| ONC | oncogene; oncology; Orthopaedic Nursing Certificate; over-the-needle catheter |
| ONS | Oncology Nursing Society |
| PdHO | pediatric hematology-oncology |
| POG | pediatric oncology group; polymyositis ossificans generalisata |