Sulen is a postdoctoral fellow at KG Jebsen Center for autoimmune disorders at Universitetet i Bergen (UiB). During his PhD project at UiB he employed phospho-specific flow- and mass-cytometry to study immune cell signaling in the context of environmental exposure. This led to the novel characterization of a p38-dependent leukocyte signaling pathway for hydrogen sulfide, a key gasotransmitter and a possible pollutant. In addition to shining a light on the role of hydrogen sulfide in inflammation, the PhD-project also triggered Sulen’s interest in the use of single-cell methodologies to study our immune system. During a 3-year postdoctoral stay at Karolinska Institutet he delved into the role of macrophages in adipose tissue and liver during obesity and insulin resistance. By using mass cytometry and single-cell RNA sequencing, he focused on the changes occurring in the adipose tissue during obesity in humans as well as mice. These experiences have provided Sulen with a cutting-edge skillset to study how our immune system affects human health.