For nine seasons and more than 200 episodes, fans of “The Big Bang Theory” have had the backs of their beloved cast. Now Kaley Cuoco, Jim Parsons and the show’s other actors have a message in return: We care about you, too.

Sadly, the message comes in the form of a public service announcement about adolescent melanoma, resulting from the death of a 17-year-old fan. But grab yourself a Kleenex and click “play” on the video above — because their powerful message might just save some lives.

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“You already know puberty has its challenges,” begins Cuoco in the PSA. “But you probably didn’t know that deadly skin cancer is one of them.”

Cuoco goes on to explain the shocking fact that adolescent melanoma is the number two killer among young people. Co-stars Parsons, Johnny Galecki and Kunal Nayyar add additional facts, urging fans between the ages of 10 and 19 to get checked out by a qualified dermatologist every year.

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Sadly, the impetus for the PSA is Claire Marie, a teenager from Maryland who died of adolescent melanoma. According to her mother, “Big Bang Theory” reruns kept her laughing during her painful final days, and when the cast heard her story they offered to help raise awareness.

“It was something she looked forward to in the evening,” mother Marianne Banister tells Baltimore TV station WJZ about Claire’s favorite show. “It was something she shared with my husband. It’s a special time that they had. A thing as simple as a TV show can bring a smile when it’s needed the most and we just wanted them to know, as a thank you from our family, and then it turned into something more.”

Banister adds that if her daughter knew about the star-powered PSA, “she would absolutely love it.” She might also love the level of awareness it will hopefully bring — in the spring, Banister’s Claire Marie Foundation screened 120 young people for melanoma and discovered precancerous growths in twenty of them.