Passage: The Istanbul Metro (Turkish: İstanbul Metrosu) is a rapid transit railway network that serves the city of Istanbul, Turkey. It is operated by Metro Istanbul (known as Istanbul Ulaşım A.Ş. before 2016), a public enterprise, controlled by the Istanbul Metropolitan Municipality. The oldest section of the metro is M1 line, which opened in 1989; it now includes 89 stations in service, with 64 more under construction.

Question: The rapid transit of Instabul is known by what name?
Istanbul Metro