Harald Janovjak works in the new research field synthetic physiology, which is the interface of synthetic biology and mammalian physiology . The Janovjak group is exploring synthetic principles for understanding and manipulating animal physiology. They have established new methods to control the signaling and behavior of nerve cells, cancer cells and key cell populations involved in metabolism. The methods provide spatial and temporal precision and include, but are not limited to, optogenetics. The Janovjak group is also focusing on understanding and manipulating cell signaling and behavior in tissues affected by disease.