On January 26, 2019, NCT 127 embarked on their first concert tour, , with shows in Korea, Japan, North America and Europe.
Doyoung joined the duo as a special DJ every Saturday.
On November 23, the group released the repackaged edition of Regular-Irregular, titled Regulate, along with the lead single "Simon Says".
Doyoung has one of the Aquarius traits: cleverness! Retrieved February 11, 2018.
With the infinite members concept that NCT has, which means members are constantly shifting into different subunits in different cities around the world, Jungwoo joined as a new member of NCT 127 in 2018 with the release of their first full-length album Regular-Irregular.
On July 6 at midnight KST, the newly formed sub-unit shared a teaser for their first music video "Fire Truck".