Cho Insun is a 1 dan professional player from Korea. On September 20 2011 he became pro after defeating Park Jeonggeun in the main draw of the 39th Myeongin tournament. This enabled him to accumulate 100 points under a new Korean qualifying system and earn pro status.
Cho was promoted 2 dan in 2012-07-12. Currently 4 dan.
Reference: Tale of three Meijins continues – Amateur player wins pro status - on Go Game Guru (archived)