Question: The three-member South Korean boy band, High4, released in 2014 a song they collaborated with which South Korean singer, songwriter and actress who signed with LOEN Entertainment in 2007?
Sentence (from "IU (singer)"): She signed with LOEN Entertainment in 2007 as a trainee and began her music career at the age of 15 with her debut album, "Lost and Found".
Relevant evidence: Yes