Bioinformatics Group, GlaxoWellcome Medicines Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, UK. mass15599@ggr.co.uk|Bioinformatics Group, GlaxoWellcome Medicines Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, UK. mass15599@ggr.co.uk|Bioinformatics Group, GlaxoWellcome Medicines Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, UK. mass15599@ggr.co.uk