Given the task definition and input, reply with output. From the given sentence, extract the phrase (often noun or verb) that carries the given relationship. The generated phrase should be present in the sentence.

Given Relationship: 'be cause of', Sentence: 'While an estimated 33 million people worldwide live with the HIV virus that causes AIDS , the numbers of new infections have been declining since 2001 and more HIV-infected people are getting treatment and living longer .'
causes