Clustering of chromosomal aberrations in the oncogenetic tree model. Maximum likelihood tree models for the AL group (groups 1 and 2) and MGUS group (groups 3 and 4) based on the CAs observed in 210 of the patients. The length of each horizontal edge “e” is proportional to −log(p_e) (eg, in groups 1 and 2, the distance of deletion 13q14 to the next inner node is 0, which means that this aberration has always occurred at this node and precedes the translocation t(4;14)). Bootstrap confidence values (percentage) for the inner edges are given. In groups 1 and 2, the translocation t(11;14) was often observed together with gain of 11q23 (88.6%) in contrast to only 16% in groups 3 and 4. Also, in 46.4% of bootstrap samples, t(11;14) was individually separated from the other 4 aberrations in groups 3 and 4.