Fig 2. Schematic representation of the different competition structures.

The strength of competition between each cell type is shown along connections in the lattice. Intraclonal competition is 1 for all cell types. ϕ, θ, and ψ are positive and less than 1. ν, μ, and ω are positive and less than or equal to 1. In competition structure III, the two distinct niches are represented by boxes. Cells that cheat in the primary tumor experience competition of magnitude θ due to, and compete with magnitude ϕ with, cells that produce the primary resource.