Definition

One of a group of proteins that play an important role in how cells respond to changing levels of oxygen. When oxygen levels in cells are low, hypoxia-inducible factors activate certain genes involved in cell growth and survival. This allows the cells to function and survive even in low oxygen conditions. Hypoxia-inducible factors may be made in larger than normal amounts by some types of cancer cells. This may cause cancer cells to grow and spread to other parts of the body. Also called HIF.