Cube Entertainment and A Cube Entertainment join forces to release their first song together “Christmas Song.” Together they are known as United Cube and the artists in this upcoming song and music video are Beast, 4Minute, G.NA, Huh Gak, BTOB, Shin Ji Hoon, Roh Ji Hoon, A Pink, and Kim Ki Ri. Junhyung and Ilhoon were revealed to have taken…