Dong Liu's team was not discouraged by the detractors in their pursuit of science. Even though they didn't see cleavage activity, instead of throwing in the towel and throwing up their hands, they looked deeper and their curious minds uncovered something interesting. Their results unmistakably verified a key characteristic of the Han NgAgo+gDNA system in zebrafish: PAM-free precise gene targeting with ssDNA guides up to 24nt in length. That was a major step forward.

Han claims that he has successfully replicated his experiments twice or more with commercially available cells. Patience is a virtue. Let's give him a bit more time.