General ---------Biology----------------------------------------------------- ------------------Online---------------------------------- Ch. 8 Membrane Structure and Function

Membrane proteins serve to join adjacent cells together.  The "tight junctions, desmosomes and gap junctions" from Ch. 7 are examples of these attachments (examples). 

Masses of cancer cells that remained joined to each other are call benign tumors.  When certain tumor cells loose their attachment and travel through the blood or lymph system to other parts of the body, metastasis of the tumor has occurred.  Cancer researchers are studying how the joining of cells breaks down, in an effort to stop the spread of tumors.