Article here
Including this quote: "Professor Robin Lovell-Badge, head of the laboratory of stem cell biology and developmental genetics at the Francis Crick Institute, who discovered the gene that determines sex in mammals, said: “In the UK, I think most [people] would use ‘sex’ to refer to anatomical appearance and ‘gender’ to ways of behaviour.”
To a scientist, he said, anatomy could appear male, female or somewhere in between, but a man who transitioned could be said to change sex."