CAD and hepatocellular carcinoma: Both CPS1 and CAD have been well established to play important roles in the development of HCC, mainly due to their relation to de novo pyrimidine synthesis.8,22–25 Although the same mechanism could also be linked to the effects of increased expression of CPS1 and CAD on prognosis, by speeding up and slowing down cell proliferation respectively, no work has been done to investigate whether this is the case.