NBN and neoplasm: A genomic comparison of the biopsies from the liver metastasis obtained upon progression on FOLFIRINOX and the primary tumor resection revealed a novel SMAD4 homozygous deletion, an MCL1 amplification, and a second frameshift mutation in NBN. This NBN mutation, which was detected only in the liver metastasis specimen, but absent in the primary resection specimen, resulted in an additional 2-nucleotide deletion (c.1154_1155del; p.K385fs*27) 8 nucleotides downstream of the initial somatic mutation (Table 1 and Fig. 1b).