CAD and hepatocellular carcinoma: Silencing of ASS1 and ASL in hepatocellular carcinoma, bladder cancer, and lung adenocarcinoma can lead to an increased supply of cytoplasmic aspartate which is a substrate of the CAD complex (carbamylphosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase) that catalyzes the first three reactions of de novo pyrimidine biosynthesis [27,28].