Melissa Claire Egan is thrilled to see that her former The Young and the Restless costar Justin Hartley has become such a big star.

"It's out of this world [to see his success]. He's still one of my best friends," Egan, 43, exclusively told Us Weekly at The Young and the Restless party celebrating 13,000 episodes of the soap opera at CBS Studios in Los Angeles last month. "He's amazing and deserves all the success. He worked really hard for it."

Egan mentioned Hartley, 47, when asked about her favorite Y&R plot twist of all time.

"I love the whole story line of when Gabriel Bingham was really Adam [Newman]. It was when Justin Hartley was playing Adam, and [there was] the big reveal of he was gay, but really he was Adam pretending to be [gay]," Egan said. "He had a face transplant, and then [there was] that big reveal when [my character] Chelsea [Lawson] finds out that this has been Adam the whole time. I love that story. I thought that was really fun and soapy and juicy."

Egan has portrayed Chelsea on the series since 2011. During that time, Hartley, Michael Muhney and Mark Grossman have stepped into the role of Adam Newman, who went from Chelsea's love interest to her ex-husband.

"We've all become such good friends," she said. "We throw each other baby showers in real life. We take care of each other. People really care about each other here, through the loss, the celebrations ... we have each other's back. The story lines are so fun, and it's great to be a working actor, but really just the friendships you build [are the best part]."

Egan also gushed about the show's "lovely" and "amazing" fans, "hundreds" of whom reached out to her after Chelsea's suicide attempt during season 50 of Y&R in 2022.

"People were so honest about how, 'This happened to my dad two weeks ago,' or 'I didn't realize I was depressed until I saw this episode,'" Egan recalled. "One person wrote, 'And now I'm going to talk to my husband about it, and I'm going to get help.' ... It meant so much to me."

The actress added that "the fan reaction" to the "mental health story line" was "so profound that it will probably forever be [her] favorite" arc from the show.

After over a decade on Y&R, Egan also reflected on the day she joined the cast.

"I started on 11/11/11. November 11, 2011," she said. "I think this show is good luck for me."