Incredible moment boy learns he's a perfect donor match for his cancer-stricken sister

An older brother is over the moon after discovering he's a perfect match to help his sister fight her cancer .

A medical professional entered the room to announce the results, saying: "One perfect match. And the other person is a five out of 10."

He was referring to the two elder siblings in the hospital room with their younger sister who was battling cancer.

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"So who wants the be the perfect match? " he enquired. The young lad eagerly raised his hand, then covered his mouth in sheer delight.

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Upon learning he was the ideal donor, the boy couldn't contain his happiness and ran around the room shouting joyfully alongside his sister.

"You can save Josie," his sister exclaimed. "I will," he assured before embracing her tightly.

The heartwarming video made its way to TikTok , melting the hearts of netizens who left comments on the post. One user remarked: "Little man has no idea of the enormity of his decision, BUT little sister will have a lifetime to remind him!!"

Another added in: "The moment he learned that he gets to be a superhero."

A different commenter noted: "He may be in pain for a while but he will have his baby sister forever!!!"

Someone else penned: "He is the best big brother omg his little sister is his whole world that's never gonna change."

However, there were a few who expressed concern over the situation. One commenter expressed mixed feelings, stating: "I want to feel happy but feel a bit ifffy, I really truly hope that child knows what comes with being a donor. Best of wishes to the family and the little girl."

Echoing this concern, another added: "I sure hope they made sure he understands what's happening and what it means to be that perfect match."