Figure 2.

Cancer across the tree of life. Phylogenetic relationships among the organisms discussed in the paper inferred from previous published trees [7,8,49–51]. This figure includes all lineages containing multicellular forms [7,8] but is not meant to denote ancestral states or all possible independent origins. Black, grey or white boxes at branch tip indicates cellularity as unicellular (white), simple or aggregative multicellularity (grey) or complex multicellularity (black) in extant species [7,8]. Red, yellow or green coloured boxes represent whether a cancer phenotype (invasion or metastasis) was reported in the literature for that lineage (red box), a cancer-like observation (abnormal proliferation or differentiation)—such as callus or galls (yellow box) or no cancer-like phenotype has been described in the literature (green box).