Article 63 human 53 Humans 46 controlled study 44 nonhuman 43 genetics 35 recombinant protein 34 Recombinant Proteins 28 female 27 Biology, life sciences 23 metabolism 23 male 22 Research & information: general 20 adult 20 Escherichia coli 19 chemistry 19 unclassified drug 19 Animals 18 animal 17 protein expression 17 Technology: general issues 16 Recombinant proteins 15 enzyme activity 15 gene expression 15 Male 14 Female 13 mouse 13 Recombinant Fusion Proteins 12 animal experiment 12 fusion protein 12