The word transferrin is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 16
Highest Scoring Words With Friends™ Play In The Letters transferrin
:
Seven Letter Word Alert: (30 words)
antsier, artsier, enfants, entrain, errants, fainter, fairest, ferrari, fireant, fraters, infants, insaner, interns, nastier, rafters, ranters, refrain, restain, retains, retinas, retrain, snifter, stainer, stirrer, tanners, tarrier, tarries, terrain, tinners, trainer