Fatigue and insomnia are a common occurrence among breast cancer patients undergoing adjuvant radiation therapy (RT) and were associated with changes in interferon γ-induced protein 10 (IP-10) and tumor necrosis factor receptor II (TNF-RII), while mental fatigue was associated with increased levels of matrix metalloproteinases-2 (MMP-2) [89]. This evidence concerns the gene MMP2 and breast cancer.