The two types of cannabinoid receptors are currently known, termed CB1 and CB2, as well as an orphan receptor, GPR55, which is being studied, and may be a third.  All three are transmembrane receptors, which mean they can send a signal obtained from outside of the cell. They are found in different concentrations in different tissues, and are known to interact differently with specific cannabinoids.  For example, CB1 receptors are found in high concentrations in the brain and central nervous system, as well as in a number of organs. CB2 receptors, on the other hand, are found largely in immune cells, as well as peripheral nerve, skin, and bone cells. 

The ECS supports cells and healthy immune system function, despite fluctuations in our external environment.*