- Stage Name: Mark (마크)
- Real Name: Mark Yi-En Tuan
- Birthdate: September 4, 1993
- Birthplace: Los Angeles, California, USA
- Height: 175cm
- Weight: 59kg
- Blood Type: A
- Education: Completed 10th grade in Arcadia High School (California)
- Hobbies: Skateboarding, Snowboarding
- Specialty: Martial arts tricking
- Languages: English, Korean and Chinese
-  Dream Knight
-  KT Olleh CF
- His favorite musicians are Chris Brown, Drake, ASAP Rocky and Tyga.
- He became a JYP Entertainment trainee in 2010.
- He lived in Brazil and Paraguay for a couple of years.
- His favorite color is red.
- His favorite foods are hamburgers and meat.