Who Designed Claire Danes' 2016 Met Gala Dress? Her Friend Made This Cinderella Gown — PHOTOS

It was the dress that people were talking about even before it hit the red carpet. But as soon as Claire Danes in her 2016 Met Gala dress finally arrived to fashion's biggest night, all everyone could talk about was the gown's amazing and innovative design. The dress lit up, people! So, who designed Danes' glow-in-the-dark Met Gala gown? It's none other than her friend Zac Posen.

The first image that we saw of the Posen-designed dress was one that didn't show which celebrity was wearing this light-up couture. Some wondered if it was pop star Katy Perry or perhaps supermodel Heidi Klum. Both were fairly good guesses until it was confirmed that the Homeland and My So Called Life star was the Cinderella hiding in the shadows. And boy, was it a good reveal.

Danes walked hand-in-hand with Posen up the stairs of the Met. The two have been besties for years (seriously, how can I become BFFs with a renowned designer like Posen?) and have collaborated on many of Danes' most memorable red carpet looks in the past.

"My style is heavily formed by my close relationship with Zac," Danes previously said. It's no wonder Posen made this marvelous creation for her to wear at the Met Gala.

Dreamy.

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All of the lights.

Danes definitely had one of the best dresses of the night, thanks to her designer BFF Zac Posen.