1. Based on the high estrogen receptor levels found in the tumor test done on this woman’s breast tissue, I believe the muted proto-oncogene is the BCL9-2 proto-oncogene. The mutation of the BCL9-2 proto-oncogene could have caused cells to grow by increasing growth factor and growth receptor production within the breast tissue cells. This leads to further cancer cell proliferation.

2. (a) Tamoxifen would be used to treat breast cancer by blocking the estrogen receptors. Estrogen is needed for estrogen-positive cancers to grow. If their receptors are blocked, the cancer cells can no longer grow or proliferate because they thrive on estrogen.

(b) Sending an antibody to the tumor with a toxin attached to it would treat cancer. The antibody