BIRC5 and neoplasm: Because systemic treatment with the antibody reduces tumor growth and increases sensitivity to gemcitabine treatment, we used western blot analysis to monitor in tumors the influence of reg4 antibody treatment on the intracellular levels of proteins associated with apoptosis (phosphorylated AKT, Bcl-2, Bcl-xL and survivin) and cell cycle (cyclin D1).