X1 was the boy band created from South Korea's sensational singing competition Produce X 101, where viewers voted week after week to whittle down 101 K-pop hopefuls to one final 11-member band. • The group included some familiar faces in the K-pop world, including Kim Wooseok, a member of the boy band UP10TION; Han Seungwoo, who is a part of VICTON; and Cho Seungyoun, who was active as a member of the Korean-Chinese group UNIQ. • X1’s first and only EP, 2019’s Emergency: Quantum Leap, set a new record for first-week sales in South Korea for a K-pop group’s debut. • Since X1 disbanded in 2020, members such as Han Seungwoo, Kim Wooseok, Kim Yohan, Lee Eunsang and Cho Seungyoun (under the stage name WOODZ) have released solo music. • Other X1 members have debuted with new groups since the group ended, including Song Hyeongjun and Kang Minhee (both in CRAVITY), Lee Hangyul and Nam Dohyon (as the duo H&D, as well in the group BAE173), and KIM YO HAN (in WEi).