In the CCA tumors in the Mayak cohort, we identified mutations in multiple genes involved in chromatin remodeling, including two recurrently mutated genes described in COSMIC but not previously reported in primary liver tumors: NUTM1 and PRDM16. NUTM1 is associated with Nut Midline Carcinoma (NMC), a squamous cell epithelial cancer characterized by a BRD-NUT translocation involving the rearrangement of BRD4 (bromodomain-containing protein 4) and NUTM144. Here, BRD4 is linked to nut midline carcinoma.