Both scientists led teams whose work has been of direct practical benefit to medicine, rather than abstract pure science with no obvious end result. Their departure is likely to be followed by others, and have a demoralising effect on the National Health Service.
When the introduction of a market within the National Health Service was announced in the late 1980s, several scientists expressed fears that research would be in jeopardy, because in the short term it adds to the cost of a hospital.
The two are Professor Bob Williamson, who is leaving as head of genetics at St Mary's Hospital, Paddington, west London, to become professor of genetics at Melbourne University; and Professor Lucio Luzzatto, head of haematology at Hammersmith Hospital, who is to take up a job at New York's Sloan Kettering Memorial Hospital. They both emphasised that they were going to excellent jobs, but the changes in funding had played a major role in their decision.
Their loss was described as a 'big blow' by Karol Sikora, a cancer expert and editor of the journal Gene Therapy, who said: 'These people are the leaders of British science. Why should they waste their time on committees carrying out hours of paperwork when they should be allowed to get on with the research that is so desperately needed?'
Over the past 20 years, Professor Williamson has pioneered gene therapy for cystic fibrosis sufferers. He headed the laboratory which was unusually productive in making significant discoveries about human genetics.
More recently scientists working under him were the first to show there was genetic damage associated with inherited forms of premature Alzheimer's disease, leading to a better understanding of the disease.
In a body blow to British research, that entire research team moved en masse to the US because they could not get proper funding for their work.
He is respected not only as a great scientist in his own right, but as one who has both led and inspired others.
He told the London Evening Standard yesterday that changes in funding of the health service which make hospitals compete for funds with one another have 'poisoned the environment between research groups who should be collaborating with one another and instead are being forced into competition.'
Professor Luzzatto said: 'What the Government is doing to the NHS is suicidal. They are repudiating its research base.'
Reacting to the two resignations, the junior health minister Baroness Cumberlege said at question time in the Lords that people often changed jobs 'for a variety of reasons including family reasons'.
She added: 'Scientists with international reputations are few in number. They work all over the world and it is not surprising that two should choose to go abroad. Many in fact choose to come to the UK from abroad and the net result if that we attract marginally more than we export.'