He completed his PhD and postdoctoral work in biochemistry and molecular pharmacology the laboratory of Dr. Kamel Khalili at Thomas Jefferson University School of Medicine, focusing on the molecular characterization of one of the JC virus isolates, Phila-1. Safak's research interest remained within the field of polyomaviruses, particularly JCV. During his postdoctoral years, he characterized viral/host protein interactions and investigated the relevance of these interactions in the JCV life cycle. His current research is on the molecular understanding of the functional roles of JCV regulatory agnoprotein in the JCV replication cycle. His lab is investigating JCV biology and agnoprotein function.