 Although they have appeared in "Judge Dredd" since the strip's earliest stories in 1977, a major story arc beginning with "Mutants in Mega-City One" in June 2007 and ending with "Tour of Duty" in July 2010 dealt specifically with their struggle against apartheid in Dredd's city, Mega-City One.Mutants are "de novo" mutations created by radiation or radioactive contamination following the Atomic Wars in 2070.Their genetic mutations (which are inherited by their children) cause them to exhibit bizarre physical deformities.