Letter from W Marzouk Fimls to Professor Bloom (Chairman of the Haemophilia Reference Centres, Haematology Department, University Hospital of Wales) re the Koate Heat Treated Trial. The letter stated that a trial exemption certificate has been applied for and that the trial would be co-ordinated by Dr Peter Jones. The writer hoped that as many reference centres as possible would be involved in the trial and welcomed the recipient's suggestions as to which centres should be approached.