source studies Blood 78 Cultured cells 18 Feces 18 Liver 14 Intestine 9 CSF 9 Urine 6 Muscle 6 Macrophages 6 Lung 6 Kidney 5 Cerebrospinal fluid 5 Heart 5 Brain 4 Cecum 4 Yeast cells 3 Stem cells 3 Uterine fluid 2 Bone marrow 2 Embryonic cells 2 Spleen 2 Tail 2 T-cells 2 Adipose tissue 2 Culture media 1 Colonic mucosa 1 Colon 1 Microglia 1 Cells 1 Neutrophils 1