Ube2Q2 is an E2 enzyme, which is part of the E1, E2, and E3 cascade responsible for ubiquitination of protein substrates. Ube2Q2 is thought to play a key role in regulating mitotic stages in cells. Its discovery was in connection with an arrest in the mitotic cell cycle. Inactivating this E2 prohibits the cell from continuing on past prophase. In cases of head and neck squamou cell carcinaoma, there is an elevated level of Ube2Q2 in the cancerous tissues. Also when the expression levels decreased, the cancerous cells were found to have a resistance to chemotherapeutic agents.