The CBR1 and its alternative splice variant form – the cannabinoid receptor type 1a (CBR1a), encoded by the CNR1 gene – are G-protein-coupled receptors, predominantly found in the central nervous system, the heart, liver, uterus, testes, and the small intestine [18]. The CBR2, encoded by CNR2, shows a 44 % amino acid sequence similarity to the CBR1 and is expressed in T and B lymphocytes, macrophages, hematopoietic cells, the brain, and other peripheral tissues, where it modulates the immune response [19–21].