CAD and neoplasm: Among them, proteins such as DEAD-box RNA helicase 18 (DDX18), DnaJ heat shock protein family (Hsp 40) member A3 (DNAJA3), platelet activating factor acetylhydrolase 1b catalytic subunit 3 (PAFAH1B3), BAG cochaperone 6 (BAG6), and carbamoyl-phosphate synthetase 2 (CAD) not only were highly expressed in LUAD tissues but also markedly secreted into the tumor microenvironment (Fig. 4D).