His research interests cover genomic instability in cancer cells and noncoding RNAs in differentiation and cancer. His laboratory identified many of the replication initiation proteins in human cells, used genomics technology to identify hundreds of origins of replication in human chromosomes, discovered a major mechanism by which human cells prevent over-replication of their DNA, and identified a novel class of circular DNA present in normal mammalian cells His laboratory has also discovered many microRNAs that inhibit cell proliferation and promote differentiation during the conversion of muscle stem cells to mature muscle and microRNAs that contribute to the phenotypes of advanced prostate cancer.