The DNAJB1-PRKACA fusion transcript is detected in 80 to 100% of fibrolamellar hepatocellular carcinomas. Detection of DNAJB1-PRKACA is thought to be a very sensitive and specific finding in support of the diagnosis of fibrolamellar carcinoma, and may contribute to tumor pathogenesis. The therapeutic targetability of this alteration remains to be elucidated.