Y4 may refer to: * Pancreatic polypeptide receptor 1, a protein that in humans is encoded by the ''PPYR1'' gene * a Mazda diesel engine *

IATA airline designator This is a list of airline codes. The table lists IATA's two-character airline designators, ICAO's three-character airline designators and the airline call signs (telephony designator). IATA airline designator IATA airline designators, somet ...

for

Volaris Volaris (legally ''Concesionaria Vuela Compañía de Aviación S.A.B. de C.V.'') is a Mexican low-cost airline based in Santa Fe, Mexico City, Santa Fe, Álvaro Obregón, Mexico City, Álvaro Obregón, Mexico City with its operating bases in Canc ...

* LNER Class Y4, a class of British steam

See also