In this study, we focused on the calcium channel Cav2.2 because (1) very little is known about its functions in cancer development; (2) it is expressed in breast cancer but not in normal tissues other than brain; (3) it is a cell surface protein which can be targeted by small molecule compounds or antibodies; (4) FDA-approved therapeutics targeting Cav2.2 is already used in clinics for chronic pain. The gene discussed is CACNA1B; the disease is breast cancer.