PTK7 and small cell lung carcinoma: We confirmed the above findings using a panel of tumor cell lines naturally expressing the varying levels of PTK7 representative of multiple cancer types, including NSCLC (H520, H1975, H1299), SCLC (H446, H69), pancreatic (BxPC3), breast (MDA-DB-468), and ovarian (OVCAR3) cancer (Figure 2).