ANXA5 and breast carcinoma: Indeed, annexin V flow cytometric analysis revealed that high p66ShcA levels in Hs578T cells resulted in an approximately 60% increase in the apoptotic rate of breast cancer cells in response to doxorubicin/PARPi treatment compared with that in p66ShcA-null cells and the parental line, which expressed lower endogenous p66ShcA levels (Figure 2A and Supplemental Figure 2C).