# A2

A2, A02, A002, A², A.II or A-2 may refer to:

## Biology and medicine

* British NVC community A2 (Lemna minor community), a plant community
* A2, the second anal vein in the Comstock-Needham system of insect wing segment naming

### Genes and proteins

* A-box 2 of insulin gene
* HLA-A2, a human MHC HLA-A serotype gene
* Ectodysplasin A2 receptor, a protein that in humans is encoded by the EDA2R gene
* Alpha-2 adrenergic receptor
* Annexin A2, a protein
* Apolipoprotein A-II, a protein
* Phospholipase A2, an enzyme
* Prokaryotic phospholipase A2, an enzyme
* Hemoglobin A2, a protein
* Proanthocyanidin A2, an A type proanthocyanidin
* Urea transporter A2, a protein
* A2, a variant of blood groups alleles A in the ABO blood group system
* A2, a subfamily of rhodopsin-like receptors

### Medicine

* ATC code A02 Drugs for acid related disorders, a subgroup of the Anatomical Therapeutic Chemical Classification System
* Brachydactyly type A2, a disease
* Noradrenergic cell group A2

## Computing

* A-2 (programming language), a follow-on to the A-0 System used on UNIVAC I
* A2 (operating system), software to run a computer

## Electronics

* DiMAGE A2, a digital camera produced by Minolta
* IBM A2, an IBM processor used in its supercomputers
* Cowon A2, a portable multimedia player from Cowon

## Gaming

* A2 Secret of the Slavers Stockade, a module in the Scourge of the Slave Lords series for Dungeons & Dragons
* Final Fantasy Tactics A2: Grimoire of the Rift

## Language

* Biu-Mandara A.2 languages, an Afro-Asiatic family of languages spoken in Nigeria
* A2, a second language level in the IB Group 2 subjects
* A2, a level in the Common European Framework of Reference for Languages

## Military

* A-2 jacket, a leather flight jacket
* A2, the military staff designation in the continental staff system for air force headquarters staff concerned with intelligence and security
* A 2, Göta Artillery Regiment designation, a former Swedish Army artillery regiment

## Music

* A due, a musical term often abbreviated to a2
* A2, a rock band that performed the song "Chosen One" in the video game Shadow the Hedgehog

## Sport

* A2 (classification), an amputee sport classification
* HEBA A2, a Greek basketball league
* A2 volleyball league (Portugal)
* A2 women's volleyball league (Portugal)
* A2, an Italian Baseball League
* A2, an Italian Volleyball League
* A2, a grade in climbing

## Television

* A2 (remote television production), a person who manages audio equipment
* A2 Stereo or Zweikanalton, a television broadcasting system
* A2 Teema, a panel discussion episode of Ajankohtainen kakkonen, a Finnish television series
* A2, common abbreviation of Antenne 2, former name (1975–1992) of French national television station France 2

## Transportation
### Air

* A-2 Savage or AJ Savage, an aircraft
* Abrial A-2 Vautour, a French sailplane built in 1925
* Antonov A-2, a Soviet glider
* Breda A.2, a 1921 Italian aircraft
* Fokker A.II, a German aircraft
* Nikol A-2, 1939 a prototype of a Polish amphibious flying boat
* Pfalz A.II, a German Idflieg A-class designation aircraft
* Reaction Engines A2, a design study for a hypersonic airliner under development
* Cielos Airlines's IATA code
* A-2, United States Navy alphanumeric code for the North American AJ Savage carrier-launched bomber
* A2, a Botswana aircraft registration code

### Rail

* Bavarian A II, an 1847 German steam locomotive model
* LNER Class A2, a class of steam locomotives
* LNER Peppercorn Class A2, a class of steam locomotives
* LNER Thompson Class A2, 3 classes of Pacific locomotives
* Milwaukee Road class A2, a 1901 4-4-2 type steam locomotive
* SP&S Class A2, an 1887 steam locomotives class
* Victorian Railways A2 class, a 1907 Australian steam locomotive
* PRR A2, a Pennsylvania Railroad locomotive classification
* Prussian A 2, a Prussian railbus model

### Road

* List of A2 roads
* Anadol A2, a 1970 Turkish car
* Arrows A2, a 1979 British racing car
* Audi A2, a 1999 automobile
* Merzario A2, see template:F1 cars 1979
* Route A2 (WMATA), a bus route operated by the Washington Metropolitan Area Transit Authority
* Audi Quattro A2, a 1984 rally car evolution of the Audi Quattro

### Sea

* HMS A2, a Royal Navy A-class submarine
* Type A2 submarine, a submarine of the Imperial Japanese Navy during World War II
* T2-SE-A2, a type of oil tanker constructed and produced in large quantities in the United States during World War II
* Sea Area A2, as defined under the GMDSS system

### Space

* Saturn A-2, a 1959 American rocket
* A-002, the third abort test of the Apollo spacecraft
* Aussat (Optus) A2, a 1985 Australian satellite

### Tanks

* M1A2, a version of the American M1 Abrams tank
* M60A2, a version of the American M60 Patton tank

## Weapons

* A2 (rocket), a German rocket design (1934)
* AUG A2 Commando, a variant of the Austrian Steyr AUG rifle
* M16A2 rifle, a variant of the M16 rifle of the United States Army
* AR-15A2, a variant of the Colt AR-15 rifle
* M16A2 mine, a variant of the M16 mine of the United States Army
* Polaris A-2, a variant of the Polaris missile of the United States Navy

## Other uses

* A2 (theater), a person who manages audio equipment
* DIN4102 A2, a flammability rating for materials ~98% noncombustible
* A2-level, an education qualification in England, Wales and Northern Ireland
* A2 milk, a trademark of the A2 Corporation
* Radio Station A2, a radio station in Lithuania
* A-2 tool steel, an air-hardening SAE grade of tool steel
* A-2 visa, a document given to officials representing a foreign government inside the United States of America
* Agence de l'innovation industrielle (AII), a French governmental agency for technological projects
* Ann Arbor, Michigan, often referred to as A2 or A$^2$
* Bird's Opening's Encyclopaedia of Chess Openings code
* A2, an international standard paper size
* A2 or SAE 304, a grade of stainless steel for fasteners
* A2, a UK Town and Country Planning use class
* A II, a painting by László Moholy-Nagy, painted in 1924
* Sea Area A2, a GMDSS system area
* YoRHa Type A No. 2, or A2, a character from the video game Nier: Automata