NEIL1 G83D variant is a low frequency polymorphism, estimated to occur in ~1% of US population (Roy et al. 2007), and is associated with primary sclerosing cholangitis and cholangiocarcinoma (Forsbring et al. 2009). NEIL G83D shows 3-8 fold reduced activity in excising DHU (dihydrouracil) from damaged DNA (Prakash et al. 2014).