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

Science and technology

* E2 reaction, a type of

elimination reaction An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one- or two-step mechanism. The one-step mechanism is known as the E2 reaction, and the two-step mechanism is known as the E1 r ...

* Honda E2, one of the predecessors of Honda's ASIMO robot * E2, a communications channel defined in the

E-carrier The E-carrier is a member of the series of carrier systems developed for digital transmission of many simultaneous telephone calls by time-division multiplexing. The European Conference of Postal and Telecommunications Administrations (CEPT) ori ...

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 Ubiquitin-conjugating enzymes, also known as E2 enzymes and more rarely as ''ubiquitin-carrier enzymes'', perform the second step in the ubiquitination reaction that targets a protein for degradation via the proteasome. The ubiquitination process ...

, a protein component of proteasome-mediated protein degradation * E2 regulatory sequence, for the insulin gene * Levuglandin E2, an aldehyde *

Prostaglandin E2 Prostaglandin E2 (PGE2), also known as dinoprostone, is a naturally occurring prostaglandin with oxytocic properties that is used as a medication. Dinoprostone is used in labor induction, bleeding after delivery, termination of pregnanc ...

, an abortifacient *

Prostaglandin E2 receptor The prostaglandin E2 (PGE2) receptors are G protein-coupled receptors that bind and are activated by prostaglandin E2. They are members of the prostaglandin receptors class of receptors and include the following Protein isoforms: * Prostaglan ...

, a human gene * Iodine-deficiency (ICD-10 code: E02) *

Estradiol Estradiol (E2), also called oestrogen, oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible ...

, 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) In cryptography, E2 is a symmetric block cipher which was created in 1998 by NTT and submitted to the AES competition. Like other AES candidates, E2 operates on blocks of 128 bits, using a key of 128, 192, or 256 bits. It uses a 12-round Feis ...

, a block cipher submitted to the AES competition by NTT *

Tungsten E2 The Tungsten series was Palm, Inc.'s line of business-class Palm OS-based PDAs. Details The Tungsten series was introduced in October 2002, created as a "prosumer" line priced at $199 to $300 to compete with the popular Sony Clie and Windo ...

, a business-class Palm OS-based handheld computer * Motorola ROKR E2, a smartphone *

Everything2 Everything2 (styled Everything2 or E2 for short) is a collaborative online community consisting of a database of interlinked user-submitted written material. E2 is moderated for quality, but has no formal policy on subject matter. Writing on E ...

, a collaborative web-based community consisting of a database of interlinked user-submitted written material

Arts and entertainment

* ''E'' (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 The Northrop Grumman E-2 Hawkeye is an American all-weather, carrier-capable tactical airborne early warning (AEW) aircraft. This twin-turboprop aircraft was designed and developed during the late 1950s and early 1960s by the Grumman Aircraft ...

, 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 The E (Eastern) postcode area, also known as the London E postcode area, is the part of the London post town covering much of east London, England. It borders the N postcode area to the west, both north of the tidal Thames. Since closure of the ...

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 Meshulam Riklis (; 2 December 1923 – 25 January 2019) was an Israeli financier and businessman. Early years Born in Istanbul to a Russian-Jewish family, Riklis grew up in Tel Aviv, and attended the Herzliya Hebrew Gymnasium high school; bef ...

, and later by Carl Icahn * E2 grade, an assessment of difficulty in rock climbing