E2

E2, e2, E02, E.II, e² or E-2 may refer to:

Science and technology

• E2 reaction, a type of elimination reaction
• Honda E2, one of the predecessors of Honda's ASIMO robot
• E2, a communications channel defined in the E-carrier standard
• G₂ (mathematics) (old name E2 or E₂), a group
• E-2 process, an obsolete film developing method for photographic transparency film

Biology and medicine

• Ubiquitin-conjugating enzyme, a protein component of proteasome-mediated protein degradation
• E2 regulatory sequence, for the insulin gene
• Levuglandin E2, an aldehyde
• Prostaglandin E2, an abortifacient
• Prostaglandin E2 receptor, a human gene
• Iodine-deficiency (ICD-10 code: E02)
• Estradiol, an estrogen steroid hormone
• Dihydrolipoyl transacetylase, the second element of the multienzyme pyruvate dehydrogenase complex
• Acireductone dioxygenase (iron(II)-requiring), an enzyme
• Haplogroup E2 (Y-DNA), a human Y-chromosome DNA haplogroup

Computing

• E2 (cipher), a block cipher submitted to the AES competition by NTT
• Tungsten E2, a business-class Palm OS-based handheld computer
• Motorola ROKR E2, a smartphone
• Everything2, a collaborative web-based community consisting of a database of interlinked user-submitted written material

Arts and entertainment

• E² (album), a 2007 album by Eros Ramazzotti

Television

• "E²", an episode of Star Trek: Enterprise
• MTV e2, a Canadian entertainment news program that airs on MTV Canada
• E2 (TV channel), a Turkish TV channel
• e2 by SKY PerfecTV!, a satellite television service in Japan operated by SKY Perfect

Transport

Air

• Northrop Grumman E-2 Hawkeye, an American carrier-based AWACS aircraft
• Fokker E.II, a 1915 German single-seat monoplane fighter aircraft
• Pfalz E.II, a German aircraft powered by the Oberursel U.I engine
• Taylor E-2, a small, light and simple utility aircraft
• Embraer E-Jet E2 family, an updated version of the E-jet family
• Eastman E-2 Sea Rover, a 1920s seaplane
• Eurowings Europe (former IATA code: E2), an Austrian airline subsidiary of Lufthansa
• Kampuchea Airlines (former IATA code: E2), a Cambodian airline

Rail

• E2 Series Shinkansen, a Japanese high-speed train
• EMC E2, an early American passenger-train diesel locomotive
• LB&SCR E2 class, a class of 0-6-0T steam locomotives designed by Lawson Billington
• PRR E2, an American PRR 4-4-2 locomotive
• CNW Class E-2, a class of 4-6-2 steam locomotives built by the American Locomotive Company in 1923

Roads and footpaths

• E02 expressway (Sri Lanka), in Sri Lanka
• E2 European long distance path, a long-distance footpath that runs from Galway in Ireland to France's Mediterranean coast
• North–South Expressway Southern Route (E2), in Malaysia
• European route E002, in Azerbaijan and Armenia
• E2 expressway (Philippines), expressway route in the Philippines
• San'yō Expressway, Hiroshiwa-Iwakuni Road, Ogori Road and Yamaguchi-Ube Road, numbered as E2 in Japan

Submarines

• HMS E2, an E-class submarine of the Royal Navy
• USS E-2, an E-class submarine of the US Navy

Other transport

• London Buses route E2, England

Other uses

• E-2 visa, a type of US visa
• E2, a postcode district in the E postcode area for east London, England
• Private E-2, a pay grade for the rank of Private in the US Army
• E2 (nightclub), a nightclub in Chicago, US
• Eternity II puzzle, a puzzle competition
• E-II Holdings, Inc., an investment holding company formerly owned by Meshulam Riklis, and later by Carl Icahn
• E2 grade, an assessment of difficulty in rock climbing

See also

• E2c, earphones by Shure
• 2E (disambiguation)
• EII (disambiguation)