Tubulin is a cytoskeletal globular protein that polymerizes to form microtubules. It plays a motile and contractile role in cell structure and cell division. During cell division, the microtubules radiate from each end of the cell form a basket like arrangement (the spindle) which helps in the movement of chromosomes to poles. The principal protein of cilia and flagella is also tubulin. Microtubules play a key role in the movement of cilia and flagella. Intermediate filaments are tough rope-like bundles or protein (keratin, desmin, peripherin, vimentin etc). Intermediate filaments provide mechanical stability to cells. They interact with microfilaments (made of protein, actin) and microtubules to form cytoskeleton.