As several articles have reported that CDCA3 was a ubiquitous proto-oncogene of human cancers, we investigated the Oncomine database to explore the expression level of CDCA3. Results from the online database showed that the expression level of CDCA3 was elevated in many types of human cancers such as breast cancer, colorectal cancer, and bladder urothelial carcinoma (Additional file 1: Fig. S1 A). Here, CDCA3 is linked to breast cancer.