Xavier's Security Enforcers (also known as the XSE) are a Marvel Comics superhero team/police force from the fictional 2070s, a time ruled by mutant hunting/killing robots called Sentinels, who at this point in time had run amok, essentially ruling Earth in order to carry out their objective to protect humanity. The XSE is formed in the fallout of the Gene War (a conflict first mentioned in X-Treme X-Men #4) and the Summers Rebellion, during which mutants and humans join forces to defeat the Sentinels.