Even Organic is GMO, in order not to get GMO you need to grow airloom varieties and even then you can't be sure.

The other thing about GMO is that it generally will not produce fertile seed.

As marijuana comercial cultivation gets going no doubt will GMO weed be the thing of the future. They can modify it any way they like. Cross it with plants with carcinogens so it kills you over time like tobacco, better for the economy that way.