I’m learning so much in this thread! So even in the womb, there exists different stimuli that can affect gene expression in identical homozygous twins? What other kinds of stimuli could that consist of? I know you said difference in absorbed nutrients, but what other things can affect gene expression? Changes in pressure? like for example, could the mom sleeping on one side for a certain duration of time cause changes in blood flow to the fetuses, etc? Thanks for putting up with all my questions, haha