ANXA5 and posterior cortical atrophy: To investigate whether SAHA and veliparib caused synergistic cell killing by inducing more cell apoptosis, we labeled cells with FITC Annexin V/PI, and assessed cell apoptosis by flow cytometry when PCa cells were treated with SAHA (1uM) and veliparib (20uM) alone or in combination (Fig. 4a-c and Additional file 2: Figure S1A-B).