Normal viruses carry genes for the proteins that are needed to make more viruses. (newscientist.com)
Sometime in the past 1,500 to 20,000 years, Y. pestis lost a set of genes for proteins called adhesins, which bind the bacteria to intestinal walls. (discovermagazine.com)
This group includes genes for proteins that influence the circulation of dopamine at the synapses between neurons — for example, proteins that clear away old messenger molecules so new ones can come through. (scientificamerican.com)