Ck19-2G2, a novel one of cytokeratin 19 fragments shed into circulation, which was identified both by CK192G2 and CK19 5H2 antibody, has been considered as one of the most sensitive tumor marker for lung carcinoma, even superior to CYFRA21-1, another CK19 fragment shed into blood in lung cancer patients [11]. Here, KRT19 is linked to lung cancer.