A multi-center study in the U.S. and China involving a total of 393 healthy subjects and 203 lung cancer patients was conducted to investigate the utility of DR-70™ immunoassay to detect lung cancer. Interference to DR-70™ test due to different disease states and blood collection procedures were also investigated. Benign and non-cancer diseases that can give rise to elevated DR-70™ levels included pneumonia, lung infection, burns, trauma due to surgery, arthritis, renal failure, sepsis etc. The study also showed that most consistent DR-70™ test results were obtained when blood was collected in vacutainers containing SST gel and clot activator. It is important that the DR-70™ test not be performed on samples of patients suffering from the aforementioned diseases. As these non-cancer disease states and improper blood collection procedures may lead to false positive results.