Earlier quoted context omitted.
Really? So like, say, Campbell Biology? That's what I've seen used in high school and colleges, and I don't recall any mention of epigenetics in it. (At least in the 7th edition one, published 2004... not sure how much it's changed since.)
So I don’t have a copy of Campbell’s underhand, but a quick google search for its table of contents brought up the ToC for 7e. Chapter 9, pg 161 covers epigenetics, p 162 gene linkages, Ch11 covers gene methylation. I’d find additional specific examples, but that’s all that’s laid out explicitly in the table of contents.
[1] https://www.pearson.ch/HigherEducation/BenjaminCummings/EAN/...