Fig. 4

Extrapontine invasion to cerebellum and spinal cord involving tumor cells from different lineages in patient 311. The two panels are drawn using the same style as Fig. 3. A Truncal variants consist of a cluster representing the founder clone (*) and cluster L with varying CCF in different tumor regions which are outlined with a dotted line; the descending nodes can arise either from the founder clone (*) or clone A. The phylogenetic tree comprised three major branches including a branch (pink) initiated by 4 CNVs shown by a thick gray arrow. A dotted arrow indicates uncertain lineage of clone H which can be a descendant from either clone C or clone G. Bi-allelic duplication such as gain of chr4 on the trunk and gain of chr1 on the yellow branch are marked with + +. B Spatial position and clonal composition of seven tumor samples and two histologically normal samples (G2 and G3) that contained low-abundance tumor cells. Extrapontine invasions involving tumor cells from both the pink (clone B′) and yellow linages (clones C, G and H) are marked by pink and yellow arrows, respectively. The identity of clone B in normal samples is marked as B^? as it is impossible to determine the presence of a PDGFRA amplicon due to the low tumor content