Kim Woo Seok wrote a letter to fans following X1's disbandment.

On January 6, the labels of the X1 members confirmed the 'Produce x 101' project group's disbandment. Kim Woo Seok has now released a handwritten letter through his agency TOP Media a day later. The letter reads:

"Hello, this is Kim Woo Seok.

We thought the same thoughts and dreamed the same dreams.

Through X1, I learned a lot and had the precious experience of receiving a lot of love from many people. When everything I thought was only a dream finally came true, you were by my side. Once again, thank you.

It was an honor to work with the X1 members, and I'll cherish the memories of our time together in my heart for the rest of my life. I ask that you send the X1 members, who I cried, laughed, and spent many days with, a kind word instead of criticism.

I also want to thank Swing Entertainment staff who worked hard on our behalf.

I think I've said this before. Though you'll no longer go by the name of ONE IT, I will never forget you.

I received a lot of love. I learned a lot. I thought I could give you a lot in return, and I'm sorry I couldn't.

I hope people will cheer me on, so that I can greet everyone as soon as possible with a new dream."