? Percutaneous Transthoracic Lung Biopsy using a Fine Needle Aspiration (FNA) biopsy is a common method of determining if a lung nodule is benign or malignant. Using imaging guidance {CT, fluoroscopy, ultrasound or bronchoscopy) a sharp needle is advanced into a suspicious area and cells are aspirated into the needle. These cells are then evaluated under a microscope and are characterized as benign, infectious or malignant. There are over 169,500 cases of lung cancer diagnosed in the U.S. and over 600,000 lung biopsies performed worldwide every year. The most common complication of this procedure is a lung collapse (pneumothorax), which occurs in 20-40% of cases. In greater than 10% of these lung collapses, the patient becomes symptomatic and requires chest tube placement and hospitalization. The development of a novel biopsy needle tract sealant that will reduce or eliminate pneumothorax would be most valuable. Proof of principal was achieved during Phase I with great results. Biopsy Sciences has decided to proceed with the safety clinical studies. 10 patient IDE was obtained from FDA which was concluded three months ago. Based on the result, FDA has granted us with a 510{k) approval for the Plug as a Site Marker. One of objectives for Phase II is to evaluate a modified version of the hydrogel as the base material with complete degradation of three months. However the focus of the investigation will be to complete the efficacy (pivotal) study in humans to use the plug to prevent / reduce the pneumothorax rate. These goals are discussed in detail in the specific aim section. There is presently no commercially available product in the United Stares to prevent or reduce the pneumothorax rate after lung Fine Needle Aspiration Biopsy (FNAB) Procedures. ? ?