[1] St Columbas Hosp, Ctr Educ & Res, Edinburgh, Midlothian, Scotland
[2] Univ Edinburgh, Inst Genet & Mol Med, Edinburgh, Midlothian, Scotland
[3] Trondheim Reg & Univ Hosp, St Olavs Hosp, Canc Clin, Trondheim, Norway
[4] NTNU Norwegian Univ Sci, Fac Med, Dept Clin & Mol Med, Fac Med & Hlth Sci, Trondheim, Norway
[5] Queen Margaret Univ, Edinburgh, Midlothian, Scotland
[6] Univ Iceland, Sch Hlth Sci, Reykjavik, Iceland