Chinese scientists have been forging ahead in experimenting with gene-editing on humans in the last few years, using a powerful tool called Crispr-Cas9 to edit the DNA of dozens of cancer patients. However, no federal body is overseeing these trials in China, and at least one such trial has lost touch with patients whose DNA was altered. Long-term followup of these patients is essential because unintended consequences of gene therapy could surface years later. (The Wall Street Journal)