Figure 1.

Successive steps of metastasis. The metastatic process begins with the proliferation of cancer cells in primary foci. The cancer cells escape from the primary site and intravasate the vascular endothelium into the bloodstream. Cancer cells interact with leukocytes and platelets protect them from immune elimination when circulating in the bloodstream. Subsequently, cancer cells are arrested by endothelial cells in the small capillaries of the secondary organ. Finally, cancer cells extravasate via the vascular endothelium into secondary sites and ultimately colonize metastatic lesions. C-type lectins are important in multiple metastatic steps.