The above described MJ-induced bioenergetic effects were observed only in mitochondria isolated from cancer cells, but not in those isolated from normal cells [19, 38, 170], supporting the general idea that MJ interacts with molecular structures on the outer mitochondrial surface of cancer cells that may be exposed in a substantially different manner than in non-cancerous cells (for instance, the HK2/VDAC complex) [24, 30, 149, 163]. Here, HK2 is linked to cancer.