Jose is married to Ana, and they have a son named Carlos. Ana has two brothers, Marco and Julio. Marco has a son named Enrique and Julio has no children. What is Enrique's relationship to Jose, Ana, and Carlos? Furthermore, who are Marco and Julio in relation to Carlos? Respond very briefly.
Enrique is the son of Marco, who is Ana's brother. This makes Enrique Ana's nephew. In relation to Jose, since Jose is married to Ana, Enrique would be his nephew by marriage, not by blood. Carlos is Ana's son, and since Marco is Carlos's uncle (the brother of his mother Ana), Enrique is Carlos's first cousin.

Marco and Julio are Ana's brothers. This means Marco is Carlos's uncle by blood, as he is a sibling of Carlos's mother. Similarly, Julio is also Carlos's uncle by blood, being the brother of Carlos's mother.