The constitutive activation of the heterotrimeric Gα proteins from the Gαq/11, Gα12/13 and Gαi/o families as well as the constitutive recruitment of β-arrestin (in green circles) contribute to cell proliferation, angiogenesis, inflammation, and aerobic glycolysis, which are important cellular functions promoting cancer development. Each signalling pathway leading to a cell function is interconnected with the pathways controlling other functions by key multifunctional proteins. Transcription factors are depicted by yellow boxes.