Thus far, two subtypes of CBR have been identified: CBR1, which is found in the brain and in certain nerve endings but also in reproductive organs, vascular endothelium and eyes [9] and CBR2, which is expressed mainly in the immune system, membranes of immune and tumour cells, spleen, bones, tonsils and thyroid gland [4,10,11]. Here, CNR1 is linked to neoplasm.