Opponents of GM technology have expressed their anger after the New Zealand Environmental Risk Management Authority approved a research experiment that involves inserting human genes into cows. The process, which it is hoped will produce milk proteins for the treatment of strokes and multiple sclerosis, involves the insertion of genes from goats, pigs, sheep, mice and humans into cattle to create genetically modified embryos. Transgenic calves will then be created by transferring the GM embryos into normal cows.