Before revision: In here presented what-if analysis we substitute a unified therapy with a ' therapy species', which is the population of heterogeneous therapies evolving accordingly to evolutionary principles. Each therapy within the species may be, at any time, either free or in the exclusive complex with one cell. The therapy is allowed to create the complex with another cell only after its current host cell has died, playing the role of a catalyst. Regarding therapeutic context, the fitnesses of the therapies reflect their respective cytotoxicities in a way which conforms to evolutionary causation.
After revision: In here presented what-if analysis we substitute a unified therapy with a ' therapy species', which is the population of heterogeneous elementary therapies, and propose a way how to turn the toxicity of the elementary therapy into its fitness in a way which conforms to evolutionary causation.