| G0 | quiescent phase of cells leaving the mitotic cycle |
|---|---|
| G1 | presynthetic gap [phase of cells prior to DNA synthesis] |
| G2 | postsynthetic gap [phase of cells following DNA synthesis] |
| GERRI | geriatric evaluation by relative rating instrument |
| HFO-A | high-frequency oscillatory [ventilation]-active [expiratory phase] |