WATCH: 9-year-old boy is cancer-free, breaks down in tears after his last chemo treatment

A 9-year-old Oklahoma boy is celebrating being cancer-free after a 3-year battle with leukemia.

Steven Cotter Jr. was diagnosed with acute lymphoblastic leukemia in August 2016, his mother Ashley Cotter told FOX 35 News. She posted a video to Facebook of Steven taking his very last chemo treatment --- and the boy can't hold back his tears of joy.

In the video, Steven is surrounded by dozens of empty pill containers -- a reminder of the long journey he has gone through to get to this moment.

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"You have never seen pure happiness till you’ve seen a 9 year old little boy cry the most happiest tears ever to be cancer free and take his last chemo treatment!!" Cotter wrote. "My baby took his last chemo crying with a smile on his face!!!! God blessed my family! Both my sons have a story to tell!!! Listen and you all will hear of them going further then the stars!!! ❤️🥰🙏🏽this is one of the most proud moments I’ve ever lived!!" 

Steven Cotter 'kicked cancer's butt' after a 3 year battle. (Ashley Cotter)

Cotter told FOX 35 News that Steven has big plans for his future.

"He always says he’s gonna work on being a NBA basketball player. He’s very passionate about basketball. Through his treatment, that was one thing he never let cancer make him quit. He played through it all!!!"

Good luck, Steven! (Note: Video provided by mother has no sound.)

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