Sverre Heim has over thirty years' experience in the field of cancer cytogenetics. He has used chromosomal markers to trace the clonal relationships among neoplastic cell populations and determined their patterns of evolution. He has served on editorial boards and scientific advisory committees and authored nearly 500 scientific publications. Felix Mitelman is an elected member of the Royal Swedish Academy of Sciences and the American Academy of Arts and Sciences, as well as the Editor-in-Chief and Founder of Genes, Chromosomes & Cancer.