The main research interest is within the histiocytic disorders, including Hemophagocytic Lymphohistiocytosis (HLH) and Langerhans cell histiocytosis (LCH). In addition to developing the first diagnostic criteria for HLH, PI of HLH-94 as well as HLH-2004. Studied underlying biological and genetic defects in HLH. Another interest is the secondary forms of HLH.