What are the similarities between A Streetcar Named Desire and To Kill a Mockingbird?

Although To Kill a Mockingbird, a novel by Harper Lee, and Streetcar Named Desire, a play by Tennessee Williams, are very different, they do have similarities. Some of them are:
Both are set in the southern U.S. The novel is set in Alabama, and the play is set in Louisiana.
Both stories address the issue of rape. Mayella Ewell falsely accuses Tom Robinson of raping her, and it is suggested that her father may have sexually assaulted her. Blanche is raped by Stanley at the end of the play.
Both stories involve a gun death. Prison guards shoot Robinson as he attempts to escape, and Blanche's young husband committed suicide by shooting himself.
Both stories feature a strong female hero. Although it might seem odd to compare Scout to Blanche since they are very different, each is a female who is opinionated and flouts societal conventions. Scout is a tomboy, and Blanche is a woman who has had many sexual partners, including an underage boy.
Both the novel and the play highlight class differences. Scout becomes aware of the way people of various social classes and races are treated in Maycomb, and Blanche, who represents a vanishing Southern upper class, finds herself living among those she considers to be of a lower class and racially inferior (Stanley, whom she labels a "Polack").
In both stories, the female protagonist experiences a loss of innocence. Scout learns about adult issues like rape, racial injustice, mental illness, and violence when she is an impressionable young child. Blanche's backstory includes her experiencing the deaths of multiple family members, financial ruin, being married to a closeted homosexual, and the suicide of her husband when she was still a young woman.
Although the novel and play are very different, they share multiple similarities.