CNR1 and neuroblastoma: BRET and PLA approaches have indeed shown that CB1R and CB2R co-localize in HEK-293T cells and SH-SY5Y neuroblastoma cells as well as puts into evidence the presence of CB1R-CB2R heteromers in a variety of rat brain regions (pineal gland, nucleus accumbens and globus pallidus) (Callén et al., 2012).