From the product description:
Muties. Freaks. Abominations. Radscum. Monsters.
The twisted victims of radiation, biochemical warfare, and mutagenic agents, mutants are outsiders, loathed, feared, shunned, and victimized by the ranks of normal humanity. Whether unique in their taint or members of stable groups of new radborn species, mutants may possess abilities strange and horrific, may be threat or ally, individuals every bit as complex and individual as any normal man.
Humans and beast alike may bear mutations, and there are whispers that such perversions of nature have occurred as to allow plants to think and move like men...
This is the world of Atomic Highway.