Now, recurrence of gallstones is another problem we have openly discussed. If you have 100 patients using only oral dissolution agents (this is the first paper) if you use oral dissolution agents and achieve a stone-free gallbladder, these patients do re-develop gallstones within five years roughly 50% of the time. This is the stone treated only with dissolution agents. There is no extra corporeal shock wave lithotripsy involved in this study. Now the question comes up: is it different when you use the extra corporeal shock wave lithotripsy, make a stone-free gallbladder and possibly select functioning gallbladder patients? So it's very important to look at that aspect. There are two studies in the literature, published studies. This is a German study. Just recently a Japanese study came in this regard and looks like similar results, and stone recurrence after successful biliary lithotripsy was 7% after one year, and increased to 31% at the end of the 5 years. How can you prevent this one? This is another project but I think oral dissolution agents, or NSAIDS, simple aspirin might be helpful for us to keep the patients gallstone free.