Given the importance of NEIL1 in the maintenance of genomic integrity following aflatoxin exposures in a mouse model (31) and the possibility that pathogenic polymorphic variants of NEIL1 (37,40–42) may affect human HCC risk, the current study was designed to investigate whether the mutagenic frequencies and spectra, including distribution of mutations across trinucleotide sequences, are altered in NEIL1-deficient versus proficient mice. Here, NEIL1 is linked to hepatocellular carcinoma.