A chemical responsible for the activation of a particular gene(noun)
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Use "epigenome" in a sentence
"Think of the genome — the DNA sequence — as being like the hardware of a computer, while the epigenome is like the software that tells the computer when, where, and how to work. here"
"But the grammar of the epigenome is changing all the time."
"The participants focused on the concept of the 'epigenome' -"