He then earned his Ph.D. in pathology from Columbia University in the United States in 1995.
[1] Chien was the associate professor of anatomy and cell biology of the College of Medicine of NTU in 1996-2006.
In 1999, he was appointed as research scientist on cell biology at University of Tokyo, Japan.
In 2007-2014, he was the deputy director of NTU Center of Genomic Medicine.
[2] In 2014, he was appointed as the Deputy Minister of the Interior, the position he held until 2016.