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Pronunciation: ton'o-fil'a-ment

Definition: A structural cytoplasmic protein, of a class known as intermediate filaments, bundles of which together form a tonofibril; a tonofilament is made up of a variable number of related proteins, keratins, and is found in all epithelial cells, but is particularly well developed in the epidermis.

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© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review date: Sep 19, 2016.