Tonofilament vs. Tonofibril — What's the Difference?

(protein) A structural filament of keratin present in the cytoplasm

Tonofibrils are cytoplasmic protein structures in epithelial tissues that converge at desmosomes and hemidesmosomes. They consist of fine fibrils in epithelial cells that are anchored to the cytoskeleton.

(biology) A structural fibril of tonofilaments found in the cytoplasm of epithelial cells