source	studies
Eye tissue	8
Blood	8
Heart	6
Liver	4
Brain	3
Cultured cells	3
Lung	1
Optic nerve	1
Plant	1
T-cells	1
Aortic valve tissue	1
Urine	1
Bone	1
Breast milk	1
Cerebrospinal fluid	1
Feces	1
LNCaP cells	1