It has been shown that polymorphisms in XRCC1, while in themselves are not associated with increased risk of lung cancer, have shown an increased risk of lung cancer in a supermultiplicative manner when associated with polymorphisms in another component of BER, poly (ADP-ribose) polymerase family, member 1 transfersase (PARP1) [41]. Here, PARP1 is linked to lung cancer.