– So we’ve discussed HLA a couple times. That stands for Human Leukocyte Antigens. Basically, these are the eyes
and ears of the immune system. So immune cells don’t have
a photo recognition system. They have a complex system
of molecules on the surface that touch and feel the environment so that the immune system
knows what it’s seeing. It has to identify part of yourself, and when a cell is infected by another, like a virus or a bacteria. So it’s this combination of
eyes and ears, if you will, for the immune system
so that it can identify cells that are infected
with a bacteria or a virus. That’s primarily the role of it.