| ETC | electron transport chain; esophageal tracheal combitude; estimated time of conception |
|---|---|
| Fd | the amino-terminal portion of the heavy chain of an immunoglobulin molecule; ferredoxin |
| FSHB | follicle-stimulating hormone, beta chain |
| FTH | ferritin heavy chain; fracture threshold |
| FTL | ferritin light chain |