Miley Cyrus is a natural woman, y'all!

The 19-year-old singer-actress showed off some extreme cleavage Sunday at the CNN Heroes: An All-Star Tribute  in Los Angeles. Wearing a plunging Robert Cavalli yellow dress, her buxom look led many to believe she'd had a boob job, but Cyrus says that's not the case.

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"Thank you for the compliment, but these babies are all mine," the former Disney star tweeted. "I wish [people would] realize you don't have to be fake to be beautiful!"

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"I'm 19!" she added. "BOOBS GROW, PEOPLE!"

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Although Cyrus didn't enhance her assets through surgery in 2011, several other stars -- including LeAnn Rimes, Nicole Richie and Teen Mom star Farrah Abraham -- opted to go under the knife.

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