OGN and small cell lung carcinoma: In some cancers OGN is down-regulated compared with normal tissues, as described in squamous cervical (63) cancer gastric cancer (64) colorectal cancer (65), vaginal cancer (63), invasive ductal breast carcinoma (66), laryngeal carcinoma (26), and thyroid tumors, while Zheng and colleagues demonstrated different expression of OGN as a marker for differential diagnosis between non-small-cell lung cancers (positive for OGN) and small-cell lung cancers (negative for OGN) (67).