,,a loss of epigenetic information is a reversible cause of aging''

While it's probably the most important cause of aging, reversing it may be not enough.

Also currently there's no way to prevent cancer cells from being created.

,,Simply titrating the amount of Yamanaka factors that we express, whether by using mRNA, or by having inducible promoters or whatever… these things will stop the mouse or the human from getting teratomas, but I don’t think they’re going to stop them from getting regular cancers, simply because the body of even people your age or my age is already chock-full of cells that have spontaneously accumulated most of the mutations needed to become cancerous.''