This is a bit silly, eh. Every cell in your body does this kind of epigenetic modification, there are a whole host of factors whose only job is to methylate DNA. Furthermore, this is not really "altering DNA", the sequence doesn't change, this is just a way to mask gene expression - if you methylate cytosines near the promoter region of a gene, RNA polymerase has a harder time sitting down and transcribing the gene, reducing its expression.<p>Neurons do this, germ cells do this, immune cells do this, every cell in the body does this.<p>What's interesting here is the specific factor (Tet3), not the occurrence of epigenetic modification. The perils of science journalism, as usual.