Upon integrating the data from these two studies we found that of the top ten genes most significantly associated with metastasis in our expression correlation analysis, two also mapped to potential QTLs: Ttc9c and Arid4b. The potential role of Ttc9c was investigated and no significant differences were detected with respect to orthotopic tumor growth or metastasis of 6DT1 mouse mammary carcinoma cells stably expressing Ttc9c compared to vector control cells (data not shown). Here, ARID4B is linked to breast carcinoma.