Wikipedia
Transilien
The Transilien is the brand name of the suburban railway service of the SNCF-owned railway network operating within the Île-de-France région. "Transilien" is a derivative of Francilien, a term commonly used to describe the inhabitants of the Île-de-France.
Transilien trains depart from Paris' main railway and RER stations (although many city-centre RER stations are run by the RATP) and the western business district of La Défense. Transilien services transported 615 million passengers in 2004.