The Mutation adds a supply of 12 purple disease cubes, 2 Mutation cards and 3 Mutation Event cards.

No purple cube is placed on the board during the game set up.
The 2 Mutation cards are placed in the Infection Discard Pile (they are not shuffled into the Infection Deck).
After dealing cards to players, but before preparing the Player Deck, the 3 Mutation Event cards are shuffled with the remaining Player cards.