Like a double-edged sword, stem cells have the potential to develop into many different cell types for regenerative medicine, but they are also the source of at least some, perhaps all, cancers. The normal and cancerous behavior of stem cells may be determined by their unique pattern of gene expression. The Cai lab focuses on the genetic mechanisms that regulate gene expression of stem cells in both normal development and tumorigenesis. We are using integrative computational and experimental approaches to identify, verify and characterize the genetic regulatory elements, e.g., the conserved non-coding DNA sequences and their interacting protein factors that involved in the regulation of stem cell gene expression. A thorough understanding of these mechanisms will provide the knowledge of stem cell development into various normal cell types as a repair system for the body, as well as a basis for the therapeutic treatments of cancers.