背景资料：FOXR2 (Forkhead box protein R2), also known as FOXN6 (Forkhead box protein N6), is a 311 amino acid nuclear protein that belongs to the FOX family and contains one fork-head DNA-binding domain. Like other members of the FOX family, FOXR2 is not abundantly expressed in normal tissues but is found at very high levels in breast cancer and primary cancer cell lines and is thought to act as a transcription factor.