User blog comment:Rassilon of Old/Ep. 122 "Agendas" discussion/@comment-4955527-20120325151548/@comment-1038387-20120325162227

Bizarro wasn't really a clone. And then he was. And then he wasn't. Or the other way round. (Retcons are confusing)

I'm not sure if the link with Luthor was established prior to Teen Titans volume 3 - wasn't the human DNA Paul Westfield's in Superboy's own title?