Recent investigations have reported changes in the expression of cell surface adhesion molecules associated with melanoma progression from in situ to invasive to metastatic tumors, including the upregulation of the integrins αvβ3, α3β1, α4β1 and α5β1, downregulation of α6β1, and enhanced expression of intercellular adhesion molecule-1, MUC18, and CD44. Current research is now focused on the function of these adhesion molecules in facilitating melanoma invasion, metastasis and evasion of lysis by effector cells, and the mechanisms involved in controlling the adhesion molecule activation state and signal transduction.