Despite never appearing in The Catcher in the Rye, Allie is a major character in the novel. Holden remembers him as a smart, kind, and talented 11-year-old who died of leukemia. Holden admires Allie’s intelligence, his sense of humor, and his ability to see through people’s masks. Allie’s death has a deep effect on Holden, and he often thinks about him throughout the novel. Holden carries around a baseball mitt that belonged to Allie, which symbolizes his love for his brother and his desire to protect childhood innocence. Allie’s character in the novel represents the pain of growing up and the loss of innocence, and Salinger uses him to explore themes of alienation, disillusionment, and the search for meaning in a seemingly senseless and cruel world.