In addition, western blot and immunofluorescence analyses demonstrated that compared with the niraparib group, STS pretreatment resulted in an increase in γH2AX and a decrease in RAD51, which meant that high levels of DNA damage and inhibition of HR repair and overloading stress make tumour cells more sensitive to chemotherapy by exhausting the stress response pathway [33]. Here, RAD51 is linked to neoplasm.