| REA | radiation emergency area; radioenzymatic assay; renal anastomosis; right ear advantage |
|---|---|
| REAR | renal, ear, anal, and radial [malformation syndrome] |
| REF | ejection fraction at rest; referred; refused; renal erythropoietic factor |
| REN | renal; renin |
| RER | renal excretion rate; respiratory exchange ratio; rough endoplasmic reticulum |