"It's not about what you know, but who you know."

This expression rings true in the entertainment industry. It doesn't necessarily mean they butchered the role because of their acting skills, but it didn't hurt that they had a connection.

Most of us know of the famous Olsen twins, who starred for more than a decade in Full House.

Other famous family mashups include Will Smith and his children. Smith's son, Jaden, played in the Pursuit of Happiness and Another Earth, and Smith's daughter, Willow, played in I Am Legend.

Fred Schepisi's 2003 comedy-drama move It Runs in the Family stars three generations of the Douglas family (Kirk Douglas, Michael Douglas, and Cameron Douglas).

Those were some more popular examples, but what about the family additions that are not so obvious?

Boyhood (2014)

Oscar nominated movie Boyhood's director Richard Linklater casted his daughter Lerolei to play the role of Samantha Evans. However, this isn't the first time she appeared in her father's movie. She also appeared in Linklater's 2001 movie Waking Life.

The Godfather: Part III (1990)

The Godfather movies are considered one of the most loved movies in American cinema. What many fans don't know is that director Francis Ford Coppola had a history of casting family members in his films. Although the character of Mary Corleone wasn't supposed to be played by Sofia Coppola at first, she ended up taking on the role.

White Chicks (2004)

We may recognize the hilarious Wayans brothers in movies like White Chicks and Dance Flick, but did you know they have an older sibling? White Chicks was directed and written by Keenan Ivory Wayans, who casted his brothers Shawn and Marlon Wayans to play the main characters in the film.

Wall Street (1987)

The best way to portray the character of a father and a son is to cast a real life duo. That's exactly what director Oliver Stone did in Wall Street. Despite having the same last name, some people are unaware that these two are related. Charlie Sheen plays Bud Fox, a junior stockbroker in New York City, and Martin Sheen plays Carl Fox, the father.

On Golden Pond (1981)

This father and daughter hit the big screen in the 80s in the American drama On Golden Pond. Henry Fonda played Norman Thayer Jr., and Jane Fonda played his daughter Chelsea Thayer Wayne.

Rocky V (1990)

Before Sylvester Stallone's eldest son, Sage, passed away in 2012, he had a chance to work with him in Rocky V. Sage played Robert Balboa, Rocky's son.

Jersey Boys (2014)

If you don't know the names of many directors, you've probably heard of Clint Eastwood. Considering his high profile in the entertainment industry, you'd think his daughter, Francesca, would get a great role in his movies, yet that's far from the truth. Francesca played Waitress #1 in Jersey Boys.

Lara Croft: Tomb Raider (2001)

It may be because this father and daughter don't share a last name that many people don't connect them together. Angelina, who played Lara Croft in Tomb Raider, changed her last name to Jolie, which is her middle name. Jon Voight played Lara Croft's father in the film.

Were any of these familiar to you? Share this story and let us know!