André-Oort conjecture for arithmetic varieties

Let $\Gamma\backslash X^+$ be an arithmetic variety, let $V$ be an algebraic subvariety, and let $\Sigma$ be the set of special points of $\Gamma\backslash X^+$ that belong to $V$. André-Oort conjecture. The Zariski closure of $\Sigma$ is a finite union of special subvarieties of $\Gamma\backslash X^+$. The source states that this conjecture has been proved, so it is included as a resolved conjecture rather than an open problem.