The word haptoglobins 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: 24
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (73 words)
abolish, absinth, agonist, albinos, alights, anglist, apologs, bashing, basting, bastion, bathing, bigshot, blights, boating, bologna, bolting, boltons, booting, galoots, gasohol, goatish, goblins, halting, hatpins, hobnail, hooping, hooting, hosting, lagoons, lapsing, lashing, lasting, lathing, longish, looping, loosing, looting, lotions, oblongs, obtains, ooliths, ooplast, options, pasting, phasing, phobias, photons, plating, platoon, plights, plosion, poohing, pooling, postbag, posting, potions, salting, sapling, shaping, shooing, slating, sloping, soaping, soloing, sooting, tabling, tabooli, tapings, tobiano, toolbag, tooling, topsail, topsoil