TOPK (also known as PBK or PDZ-binding kinase) was first reported by Abe et al. in 2000 [6], and it is a Ser/Thr protein kinase overexpressed in hematologic tumors, breast cancer, melanoma, colorectal cancer, prostate cancer, cervical cancer, bladder cancer and lung cancer [7,8,9,10,11,12,13,14]. The gene discussed is PBK; the disease is breast cancer.