Different cells express different messenger RNAs transcribed from the genome; these RNAs encode downstream proteins and vary across cell types.

“What's sort of happening specifically? And so first level, what we typically have, one of the first levels is that, you know, per cell different stuff is being read off of the genome, right? And these messenger RNAs, which then sort of encode the various downstream proteins, well, these are sort of differently expressed as one says in, in, in different cells.”