This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'Connexins are associated with which of the following? \nSelect and explain. \nA. Desmosomes, B. Hemidesmosomes, C. Gap junctions, D. None of the above', 'role': 'user'}, {'content': "Answer: C \nExplanation: At gap junctions, the intercellular space narrows from 25 nm to 3 nm, and units called connexons in the membrane of each cell are lined up with one another. Each connexon is made up of six protein subunits called connexins. They surround a channel that, when lined up with the channel in the corresponding connexon in the adjacent cell, permits substances to pass between the cells without entering the ECF. Ref: Ganong's Review of Medical Physiology 23rd edition, Chapter 2.", 'role': 'assistant'}]