| REN | renal; renin |
|---|---|
| RER | renal excretion rate; respiratory exchange ratio; rough endoplasmic reticulum |
| RF | radial fiber; radio frequency; receptive field; regurgitant fraction; Reitland-Franklin [unit]; rela... |
| RFI | radiofrequency interference; recurrence-free interval; renal failure index |
| RFS | relapse-free survival; renal function study; rotating frame spectroscopy |