Past research of Maitland-van der Zee focused on precision medicine in among others cardiovascular medicine, airway diseases, hematology, oncology, and adverse drug reactions. Her recent research is focused on airways diseases, in particular asthma in children and adults. Precision Medicine refers to the tailoring of medical treatment to the individual characteristics of each patient. It involves the application of “omic” analysis and systems biology to analyze the cause of an individual patient's disease at the molecular level and then to utilize targeted (possibly in combination) to address that individual patient's disease process.