X

Where the this movie's titile "X" comes from?

I am curious as to the origin of the title X of this film. Possible origins are listed below.

X factor

The "X Factor" is a phrase used to describe a noteworthy quality that makes someone or something unique, often in a way that cannot be easily defined or quantified. It’s that mysterious, indefinable element that makes an individual stand out. In a person, it could refer to charisma, charm, or the innate ability to command attention or excel in a particular field. In a project or product, it might be an innovative feature that sets it apart from all others on the market.