Dr. Nichols investigates the genetic susceptibility of pulmonary arterial hypertension. His lab was instrumental in identifying the first gene associated with the disorder. He is director of the NHLBI funded National Biological Sample and Data Repository for PAH, an effort to bank biological samples, clinical and genetic data for 3,000 PAH patients. Genetic analysis of murine pulmonary hypertension and Parkinson disease are also ongoing research interests.