His group has analyzed in mammalian systems how the cilium regulates critical developmental pathways and how the loss of the cilium causes abnormalities in left-right body axis specification, limb and tooth patterning, skin, and hair follicle morphogenesis, and impairs endochondral bone formation. His group is also providing critical fundamental insights into the connection between ciliary dysfunction and cystic kidney disorders, and novel roles for neuronal cilia in the regulation of satiation responses, disruption of which causes obesity and type II diabetes.