Here is something amazing:
Basically, cells in your body have been shown to give up their mitochondria, and transfer them to other cells! So, there's a way to transfer genetic material beyond the usual routes of reproduction and epigenetic effects.
They discuss how this could be used as a new type of therapy, called mitotherpy, where raw mitochondria are injected into the body, which are then absorbed by cells:
One tangible prospect emerges from Chinese researchers who have used mitotherapy to improve cognitive and motor performance in aged mice. Their results showed that the heterozygous mitochondrial DNA of both aged and young mice coexisted in several tissues shortly after intravenous injection of young mitos. It is interesting that the most susceptible population for Covid-19 are the elderly, precisely those with the highest probability of age-associated mitochondrial dysfunction. Furthermore, there have been a number of young people that have succumbed to Covid-19.
What if you got a blood transfusion or an organ transplant?... Are some of the mitochondria from the donor cells incorporated into all your other tissues?
Think about the prospects for anti-aging therapy: you could freeze some of your cells at a given age, or just produce stem cells from your body, to make young cells with young mitos; and then strip the cells, releasing the mitos; and inject them into your body. Would that slow aging?
Another thing I have wondered about is the transfer of conformal protein structure information. It is known that misfolded proteins ingested into your body can cause other proteins to misfold, resulting in "prion diseases" like Creutzfeldt-Jakob disease (CJD). What I wonder is whether there are benign transfers of protein structural information, through the food that you eat, for example.
I suppose we will have to wait and see whether this is ever discovered, probably by accident (like many discoveries in biology).
It seems there is still a lot we don't know -- and, therefore, a lot of potential therapies!