Recent studies have demonstrated that overexpression of CBX3/HP1γ negatively impacts prognosis by promoting cancer development and growth in osteosarcoma [20], prostate cancer [21–23], colon cancer [24, 25], pancreatic cancer [26, 27], tongue squamous cell carcinoma [28, 29], breast cancer [30], and lung cancer [31–33]. The gene discussed is CBX3; the disease is breast cancer.