| Radioisotopes | Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh'... more | 28 | 101 | Details |
| Radiolabeled Somatostatin Analogs | Not Available | 1 | 6 | Details |
| Radioligand Therapeutic Agent | Not Available | 1 | 2 | Details |
| Radiopharmaceutical Activity | Not Available | 43 | 75 | Details |
| Radiopharmaceuticals | Compounds that are used in medicine as sources of radiation for radiotherapy and for di... more | 29 | 62 | Details |
| raf Kinases | Not Available | 0 | 0 | Details |
| Rana pipiens | Not Available | 1 | 1 | Details |
| RANK Ligand Blocking Activity | Not Available | 1 | 1 | Details |
| RANK Ligand Inhibitor | Not Available | 1 | 1 | Details |
| Ranunculaceae | The buttercup plant family of the order RANUNCULALES, class MAGNOLIOPSIDA. The leaves a... more | 2 | 9 | Details |
| Ranunculales | An order of flowering plants also known as the buttercup family. | 2 | 9 | Details |
| RAS GTPase Inhibitors | Drugs that inhibit RAS GTPase. | 3 | 23 | Details |
| Reactive Nitrogen Species | Nitrogenous products of NITRIC OXIDE synthases, ranging from NITRIC OXIDE to NITRATES. ... more | 2 | 16 | Details |
| Reactive Oxygen Species | Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reac... more | 15 | 235 | Details |
| Rearranged during Transfection (RET) Inhibitors | Not Available | 2 | 37 | Details |
| Receptor molecules, native or modified | Molecules, typically proteins, that bind a specific receptor and elicits a cell signal.... more | 0 | 0 | Details |
| Receptor Protein-Tyrosine Kinases | A class of cellular receptors that have an intrinsic PROTEIN-TYROSINE KINASE activity. | 2 | 3 | Details |
| Receptor Protein-Tyrosine Kinases, antagonists & inhibitors | Not Available | 4 | 34 | Details |
| Receptor Tyrosine Kinase Inhibitors | Not Available | 4 | 75 | Details |
| Receptor, Adenosine A1 | Not Available | 2 | 5 | Details |
| Receptor, Anaphylatoxin C5a, antagonists & inhibitors | Not Available | 1 | 1 | Details |
| Receptor, Cannabinoid, CB1, agonists | Not Available | 0 | 0 | Details |
| Receptor, Cannabinoid, CB1, antagonists & inhibitors | Not Available | 6 | 10 | Details |
| Receptor, Cannabinoid, CB2, agonists | Not Available | 1 | 1 | Details |
| Receptor, Cholecystokinin A, agonists | Not Available | 1 | 1 | Details |