Compared with other cancer types in which the OSNA method has been reported to be helpful for the detection of CK19, such as cervical (14.3–16.0), colorectal (13.3–14.3), endometrial (12.1–14.0), thyroid (11.0–13.3), head and neck (7.8–14.7), and prostate cancer (10.8–12.4), CK19 expression levels in SCLC samples was equivalent. This evidence concerns the gene KRT19 and small cell lung carcinoma.