 Furthermore, we plan to perform single cell analysis of gene mutations and gene expression. Next generation genomic sequencing of single CTCs may allow us to determine a genetic signature for colorectal CTCs and to identify novel biomarkers for CTC detection, disease monitoring, and therapeutic efficacy. Furthermore, the extent of heterogeneity among initially isolated CTCs, which can be compared to the primary tumor and CTCs growing in vitro, will be studied. Single CTC analysis has the potential to identify novel gene and signal transduction pathways that are activated in CTCs and to compare this genomic profile to that of the primary tumor and patient metastasis. Single cell genomic analysis in CTCs is highly innovative and will provide important information for disease monitoring as well as shed light on the underlying biology of CTCs. 