XRCC4 and ovarian carcinoma: Significant expression changes were also confirmed by RT-qPCR for some genes involved in homologous (HR) and non-homologous end joining (NHEJ) DNA damage-repair mechanisms in ovarian cancer, such as XRCC1 [55] in EOC-CC1, and XRCC4, RAD51 and BRCA2 [56] in OSPC2.