Circulating tumor cells are commonly referred to as circulating tumor cells when they enter human peripheral blood. The detection of circulating tumor cells can be effectively applied to in vitro early diagnosis, rapid evaluation of chemotherapeutic drugs, individualized treatment including prochlorine screening, detection of drug resistance, monitoring of tumor recurrence and development of new tumor drugs. Circulating tumor cells (CTCs) are shed from the primary site tumor tissue into the blood stream to initiate the distal metastatic process. Although the number of circulating tumor cells is very small, these cells lead to the hematogenous dissemination of tumor cells through specific cellular signaling pathways. A study recently published in Nature used microdevices to efficiently capture CTCs in a mouse model of endogenous pancreatic cancer and sequenced these cells with single-molecule RNA to find that Wnt2, a candidate gene for CTCs, is highly expressed within circulating tumor cells. Expression of Wnt2 in pancreatic cancer cells resulted in suppression of apoptosis in tumor cells with loss of nesting and an increased propensity of tumor cells to metastasize in vivo. This effect was associated with upregulation of fibronectin and inhibition of MAP3K7 (also known as TAK1 protein) kinase. Clinical data also showed that high expression of Wnt signaling was found in the CTCs of 511 pancreatic cancer patients. Therefore, further molecular analysis of circulating tumor cells to identify candidate therapeutic targets to prevent the spread of distal cancer is warranted.