**3. Conclusion**

Elucidating the molecular mechanism of metastasis can improve efficient drug design and therapies. Currently, no distinguishable cellular behavior detected between normal and metastatic cells. Further, invasion is not a unique property for cancer cells. However, invadopodia may provide some insights and metastatic cells also proliferate without differentiating. Plus, the colonization stage of metastasis provides therapeutic opportunities as the cells are proangiogenic for long periods. All these differences may provide targets for both drug design and therapeutic approaches. In spite of all these differences, it is relatively easy to compare two distinct stages/properties of the tumor and may provide plethora of data.
