NOTCH1 and hepatocellular carcinoma: We analyzed a total of 111 mutations, finding cosmic mutations in NRAS, PTEN, KRAS, IDH2, STK11, ERBB4, VHL, PIK3CA, APC, SMO, and NOTCH1 genes uniquely present in all sequential generations of CDX‐derived liver tissue (Table 1 and Fig. S2); of note, PIK3CA gene cosmic mutation (COSM21451) is known to be associated with HCC (Forbes et al., 2017).