HIF-2, or Hypoxia-Inducible Factor 2, is a protein that plays a crucial role in how cells respond to low oxygen levels, a condition known as hypoxia. It helps regulate various genes involved in processes like cell growth, metabolism, and blood vessel formation, making it essential for adapting to changing oxygen availability. This factor is part of a larger family of proteins that includes HIF-1, which also responds to hypoxia. HIF-2 is particularly important in certain tissues, such as the kidneys and lungs, and has been studied for its implications in diseases like cancer and renal disorders.