The PRKCDBP tumor suppressor gene has been shown to be: (i) significantly down-regulated in both breast cancer brain metastases and primary brain cancer with brain relapse compared to primary tumors without relapse or bone metastasis [49]; (ii) altered in colorectal cancer [50]; and (iii) contributing to the malignant progression of several tumor types [51–54]. The gene discussed is CAVIN3; the disease is brain cancer.