AB In response to a letter by D. R. Ort (Nature (London) (1997) 385, 290) it is suggested that the claim that foods from genetically engineered plants are essentially the same as those from conventionally bred plants (from a biosafety perspective) is not easily reconciled with the emphasis on their difference from such plants when demonstrating novelty and non-obviousness for patenting purposes. It is argued that a European draft directive on the protection of biotechnological inventions should be rejected pending a full discussion of the rights, responsibilities and means of intellectual property protection within society. The issue of labelling of genetically engineered soyabeans has highlighted the importance of ethical considerations. The patentability of DNA from individual humans, of human embryos, and of animal and plant materials is questioned.