| GEX | gas exchange |
|---|---|
| HPAC | high-performance anion-exchange chromatography; hypothalamo-pituitary-adreno-cortical |
| HX | histiocytosis X; hydrogen exchange; hypophysectomized |
| IEC | injection electrode catheter; International Electrotechnical Commission; intraepithelial carcinoma; ... |
| IET | intrauterine exchange transfusion |