C-erbB2 used as a marker for determining treatment and prognosis of breast cancer. The most often method used to evaluate c-erbB2 in tissue samples is by immunohistochemistry (IHC). Another method to evaluate c-erbB2 is measure the level of ECD (extra cellular domain) c-erbB2 were detached from the cell surface in serum and saliva. Saliva is used as a diagnostic tool because it can be collected…