A U.S. Marine donated half of his liver to complete stranger battling liver disease. Corey Weber learned in the Fall that you could donate a portion of your liver to someone in need of a transplant. He started filling out an application when he got word of Katie Sproull's story."In the middle of the application process, my wife shared Katie's story and I was like 'she's local, this is crazy,'" said Weber. "Not only is she local, she's O negative I know how hard it is to find O negative, I'm O negative as well."Sproull has been battling Primary Biliary Cirrhosis (PBC) for over a decade. Medical experts say while the disease can be maintained with treatment, there is no cure."It is a slow destruction of the biliary ducts of the liver. So your liver is cleaning out all of your toxins and they go out through, your bile ducts start to become unusable, they have a hard time filtering things out," Sproull told Pittsburgh's Action News 4. "There's (medicine) that will slow the progression of them. Some people respond to the meds, I unfortunately, did not."Sproull said after a doctor confirmed she was in stage four of four, she knew a transplant was what she needed. However, due to a long list of names before her on a list, she decided to take matters into her own hands and post her story on Facebook. "Eventually you end up with a transplant, you end up on the United Network for Organ Sharing (UNOs) list waiting for a liver transplant along with 23,000 other people."It was in February Sproull made the post and two days later, Weber's wife messaged Sproull about the possibility of her husband donating his liver. The two also discovered they only live about 2 miles apart, and Sproull works at the same company as Weber's wife.After lots of thorough tests at UPMC, Weber was cleared to donate half of his liver to Sproull. The two went out to dinner to meet on July 1 and had the procedure done July 14."I don't even think Corey actually even understands the magnitude of what he's done. He seems to just be that person," said Sproull. "I have a 12-year-old and 16-year-old, I got a lot of time to spend with them and at that rate, it wasn't going to be there."Medical experts report the liver can regenerate and grow back to normal size for both the donor and recipient. Weber said his liver is expected to be back to full size with no issues in about two months. Sproull said her's will take about three months. Both Sproull and Weber spent less than a week in the hospital.Sproull said she's feeling "great" and has had no itching, which is a symptom of PBC that she struggled with for years. "Even though PBC makes you exhausted, I just never sleep because (I was) itchy all the time. And three days post-op, Corey had asked me how the itch was, and it was the first time I said 'oh my God I haven't itched.'" Sproull and Weber hope their story inspires others to donate."There are thousands of people that die on this list every year and there are billions of people out there with healthy livers," said Sproull. "Nobody has to be on that list, there doesn't even need to be a list." "For me, being generally healthy and especially with UPMC and the donor team doing the background check on your health the way they do, how thorough they are. I just trusted that I could do this and they felt safe with me doing this, that I was a good candidate and that everything was going to be OK," said Weber. "If you have an opportunity to do something like this, why not do it? This is obviously a huge impact to her life, to her kids' life."UPMC encourages anyone with needs to come in for an evaluation. To learn more about UPMC's Living Donor Program, click here.