in vitro study human 290 Article 257 Humans 231 controlled study 222 nonhuman 163 In Vitro Techniques 117 unclassified drug 110 human cell 109 metabolism 92 Animals 91 animal 87 procedures 87 male 82 chemistry 81 drug effect 81 animal experiment 78 in vivo study 70 female 67 mouse 66 genetics 61 animal cell 55 animal tissue 51 animal model 50 cell proliferation 50 comparative study 46 pathology 46 priority journal 46 protein expression 46 Male 41