You can now modify the genes of large animals, and the largest animal we are concerned with is the human.

Childhood depression tends to be more common in inner cities, being most frequently related to serious social deprivation, bullying, domestic violence, wartime experience and famine. It is, for example, a serious problem among children who are traumatised refugees.

You can't be judgmental about babies. They are all have different needs. I was left with an enduring hatred of cheese because it was forced down me when I was young.

I think it's important for scientists to be a bit less arrogant, a bit more humble, recognising we are capable of making mistakes and being fallacious - which is increasingly serious in a society where our work may have unpredictable consequences.

Both in Britain and America, huge publicity has been given to stem cells, particularly embryonic stem cells, and the potential they offer. Of course, the study of stem cells is one of the most exciting areas in biology, but I think it is unlikely that embryonic stem cells are likely to be useful in healthcare for a long time.

Surgeons always underestimate the pain and disability involved in what they do to people.

We can't any longer have the conventional understanding of genetics which everybody peddles because it is increasingly obvious that epigenetics - actually things which influence the genome's function - are much more important than we realised.