CRISPR-CAS9 for genome editing. Briefly, it allows us to identify particular bits of DNA and modify one or more bases. It's a very new biotechnology (research essentially began within the last 10 years) which applies to essentially all species we've tested it on. It is cheap and so easy to perform that I could probably teach 99% of HN to do it in a week's training or less. It's still not as accurate as we need it to…
I am not sure that human genome edition is something I would consider "exciting". It adds a lot of ethical questions, I am thinking about the kind of uses "I want my child to have blue eyes" in particular.
If someone has a blood cancer (i.e. they are damaged at a DNA level) and can only currently be cured by a danagerous stem cell transplant and then the ability comes along to fix their DNA back to what it previously was at the genetic level wouldnt you agree it would be more unethical to not allow them access to that treatment?