I want to know the answer to the following question:
What does the protein hemagglutinin bind together?
All the background I'm provided with is that "The ability of the viral protein hemagglutinin to bind red blood cells together into a detectable matrix may also be characterized as a biochemical test for viral infection, although strictly speaking hemagglutinin is not an enzyme and has no metabolic function.". Is that enough to answer the question?
Answer: yes