Here's a hot take from the NYT:

Quote:

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Scientists are also studying why most children seem less affected than adults, a question that could help them learn more about how the virus works in general. Theories include that cells lining the blood vessels and heart change as we age or that children’s lung cells express lower levels of proteins that help the virus enter the cells and replicate.

https://www.nytimes.com/2020/05/11/health/cor...n-icu.html

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All this does suggest epigenetic differences, but CCR5's role is definitely not clear... that suggests to me ACE2 more. YMMV