The US government is also funding [PPL] to develop "immunocows" which generate cancer-fighting human antibodies, while elsewhere, a partnership between Roslin and the US firm Viragen is investigating the possibility of genetically engineering chickens to produce "golden eggs" with similar anti-cancer properties.

PPL also plans to use gene targeting to create "immunocows", cows with their own immune systems knocked out and replaced with human immune systems. This would allow the firm to extract gamma globulin, a group of plasma proteins used in the treatment of and immunisation against certain diseases, and which is now obtained from human blood, from cows instead.