| nitric oxide → IsA → gas | 0.67 | |
| nitric oxide → IsA → a messenger molecule | 0.43 | |
| nitric oxide → IsA → a free form gas | 0.37 | |
| nitric oxide → IsA → colourless gas | 0.35 | |
| nitric oxide → IsA → naturally-occurring compound | 0.31 | |
| nitric oxide → IsA → short-lived gas | 0.25 |