[1] He has been a research scientist at the University of Washington in Seattle, professor of cell biology at the University of Gothenburg, and visiting professor at Harvard Medical School.
His research concerns the interplay between the immune system and blood vessels, and the cause of atherosclerosis.
[2][3] Important contributions include the discovery of inflammatory cells and signals in atherosclerotic arteries and of protective immune responses against this disease.
In 2007, Hansson was elected member of the Royal Swedish Academy of Sciences and served as its secretary general from 2015 until 2022.
[4] He is a scientific advisor to Humanitas University in Milan, the Centre of Molecular Inflammation Research in Trondheim, and the Leducq Foundation.