RER may refer to:

Transport

In France

* , or , the commuter rail service serving Paris and its suburbs * , now called , commuter rail service serving

Geneva Geneva ( , ; ) ; ; . is the List of cities in Switzerland, second-most populous city in Switzerland and the most populous in French-speaking Romandy. Situated in the southwest of the country, where the Rhône exits Lake Geneva, it is the ca ...

(Switzerland),

Annemasse Annemasse (; Franco-Provençal, Arpitan: ''Anemâsse'') is a Communes of France, commune in the Haute-Savoie Departments of France, department in the Auvergne-Rhône-Alpes Regions of France, region in Eastern France. Even though it covers a relativ ...

(France) and its suburbs

In Belgium

* ('Brussels Regional Express Network'), the commuter rail service serving Brussels and its suburbs and commuters * ('Ghent Regional Express Network'), the commuter rail service serving Ghent and its suburbs and commuters

In Switzerland

* , the name used for the Bern S-Bahn in French speaking areas. * , commuter rail service serving Vaud and its suburbs * , commuter rail service serving Fribourg and its suburbs * , the name used for the Basel S-Bahn in French speaking areas. * , now called , commuter rail service serving

and its suburbs

In Argentina

* , a planned commuter rail service in

Buenos Aires Buenos Aires, controlled by the government of the Autonomous City of Buenos Aires, is the Capital city, capital and largest city of Argentina. It is located on the southwest of the Río de la Plata. Buenos Aires is classified as an Alpha− glob ...

In Canada

* GO Regional Express Rail, now known as ''GO Expansion'', a planned commuter rail service in Toronto and its suburbs

Other uses

* Rebuilt Reading electric multiple units * The Real Estate Roundtable, a non-profit public policy organization that represents the interests of real estate *

Real exchange rate In finance, an exchange rate is the rate at which one currency will be exchanged for another currency. Currencies are most commonly national currencies, but may be sub-national as in the case of Hong Kong or supra-national as in the case of ...

, the purchasing power of a currency relative to another at current exchange rates and prices * RēR, the standard abbreviation for the label Recommended Records * '' Resident Evil: Revelations'', a Capcom game * Respiratory exchange ratio, the ratio between the amount of carbon dioxide produced in metabolism and oxygen used *

Rough endoplasmic reticulum The endoplasmic reticulum (ER) is a part of a transportation system of the eukaryotic cell, and has many other important functions such as protein folding. The word endoplasmic means "within the cytoplasm", and reticulum is Latin for "little n ...

, a type of endoplasmic reticulum protein-manufacturing ribosomes {{Disambiguation