Related by context. Frequent words. (Click for all words.) 52 tumor cells 49 fibroblasts 49 macrophages 49 epithelial cells 48 cancerous cells 47 malignant cells 47 lymphocytes 47 immune cells 46 pancreas 46 bloodstream 45 neutrophils 45 cytokines 44 proteins 44 cells 44 antibodies 42 lipids 42 secretion 41 intracellular 41 lung tissue 40 bacteria 40 molecule 40 nerve cells 40 secretions 40 cerebrospinal fluid 39 gastrointestinal tract 39 mitochondria 39 toxin 39 glutamate 38 gland 38 cell membrane 38 tissues 38 blood vessels 37 cell membranes 37 hair follicles 37 lymph 37 lymphatic system 37 epidermis 37 hemoglobin 37 liver 36 molecules 36 uric acid 36 respiratory tract 36 intestine 36 intestinal tract 36 nitric oxide 36 neurotransmitter 35 lactic acid 35 amniotic fluid 35 digestive tract 35 platelets 35 small intestine 35 uterus 35 glucose 35 clotting 35 nanoparticles 34 neurotransmitters 34 muscle tissue 34 metabolism 34 excretion 34 spores 34 thyroid gland 34 spinal fluid 33 capillaries 33 metabolized 33 intestines 33 soluble 33 sugars 32 excreted 32 placenta 32 stress hormones 32 lungs 32 clot 31 toxins 31 nutrients 30 left ventricle 30 urethra 30 neurotoxin 30 ions 29 occurs naturally 29 water soluble 29 esophagus 29 saliva 29 mucus 29 nasal passages 29 metabolize 27 digestive 27 particles 27 intravenously 26 circulatory 26 aorta 26 excrete 25 clots 25 oxygen 25 fluids 25 arteries 24 stomach acid 23 trachea 23 pores 22 inhaled 21 ingested 21 tiny particles