and Jaehyun were announced as the DJs for SBS Power FM's new program, NCT's Night Night, which began airing on March 20. In January 2018, Taeil, Doyoung, and Jaehyun released the single "Timeless" under NCT U as part of the SM Station project. Later that moth, SM Entertainment unveiled NCT 2018, a project involving all 18 members of NCT at the time. On January 30, SM released a video titled "NCT 2018 Yearbook #1", which featured all prior members and introduced new members Kun, Lucas, and Jungwoo. In February, NCT released a series of online documentary videos titled NCTmentary as part of the NCT 2018 project. NCT released their first full-length album, NCT 2018 Empathy, on March 14. The album featured six singles, showcasing each sub-unit of NCT: "Boss", "Baby Don't Stop", and "Yestoday" by various NCT U lineups; "Go" by NCT Dream; "Touch" by NCT 127; and "Black on Black" with all 18 members. NCT topped Billboard Emerging Artists chart on May 5, marking the first time that a K-pop act had led the list. Mark graduated from NCT Dream after the release of their second EP, We Go Up, in September. On September 11, Xiaojun was the first of the then-undebuted WayV members to be introduced through SM Rookies, with Hendery and Yangyang following on September 13 and September 15, respectively. Jungwoo was added to NCT 127 in October, with the release of their first studio album, Regular-Irregular. Winwin did not participate in promotional activities of the album's reissue, Regulate, in order to prepare for his debut with WayV. 2019–2020: Debut of WayV, NCT Dream restructure and NCT 2020 Resonance On December 31, 2018, SM Entertainment announced NCT's fourth sub-unit, WayV () under Label V. The unit would be based in China and consists of seven members: Kun, Winwin, Ten, Lucas, Hendery, Xiaojun and Yangyang. The sub-unit officially debuted on January 17, 2019, with a Chinese version of NCT 127's "Regular". Their debut single album, The Vision, was released digitally and included a Chinese version of NCT 127's "Come Back" and an original song titled "Dream Launch". On December 13, NCT U (consisting of Taeil, Doyoung, Jaehyun and Haechan) released "Coming Home" as part of the SM Station X project. After wrapping up album promotions for their EP Reload in April, NCT Dream abandoned their original concept in which members "graduate" from the sub-unit upon reaching age of