Receptors

Major nodes: ClassI | OR1/3/7 | OR2/13 | OR2M/T/V | OR4/12 | OR5/8/9 | OR5A/AN | OR6/10/11 | OR10D/G/S | OR14 | OR51/52 | Schiff6

────────────────────────────────────┬───┬───┬────── OR9A2
                                    │   │   └────── OR9A4
                                    │   └───┬────── OR9I1
                                    │       └───┬────── OR9Q1
                                    │           └────── OR9Q2
                                    └───┬───┬────── OR9G1
                                        │   └────── OR9G9
                                        └────── OR9G4