Tirbanibulin is a microtubule inhibitor developed for the topical treatment of actinic keratosis. The mechanism of action is not fully understood. However, it is known that tirbanibulin inhibits proliferation of keratinocytes through inhibition of tubulin polymerization and disruption of Src tyrosine kinase signaling. This results in disruption of the intracellular microtubule network, resulting in cell cycle arrest and apoptosis of keratinocytes.