Although our study showed significant increase in high CK19 in cases of NSCLC compared with SCLC as reported in a number of previous trials; however, there was no significant difference between different histological types of NSCLC in contrast to a number of previous trials, which showed higher incidence in SCC, this is because in our study all cases of NSCLC of different histology types showed high CK19. Here, KRT19 is linked to non-small cell lung carcinoma.