Cancer Research UK starts DNA matching research
About 9,000 cancer patients are being asked take part in new gene tests which could improve therapies.
Samples from tumours will be tested for gene faults, and testing laboratories in London, Cardiff and Birmingham will compare the outcome of treatments.
Cancer Research UK will ask the patients to take part in the first phase of the project.
Five Welsh hospitals are also taking part.
Prof Malcolm Mason, of the Cardiff Experimental Cancer Medicine Centre, called it an exciting initiative.
Health Correspondent Hywel Griffith reports