This Monday, Nov. 11, 2013 photo shows identical twins Kristen Maurer, left, and Kelly McCarthy at Kelly's mother-in-law’s house in Beecher, Ill. The 34-year-old sisters from Crown Point, Ind., have shared a lot in their lives so when Kelly was diagnosed with breast cancer in 2011, she urged Kristen to get tested, too. Kristen also was diagnosed with breast cancer. Now the twins are sharing a medical rarity: Kristen donated skin and fat tissue for Kelly's breast reconstruction surgery that was performed at the University of Chicago Medical Center by breast cancer surgeon, Dr. David Song on Tuesday, Nov. 12. (AP Photo/M. Spencer Green)CHICAGO (AP) — an Identical twins Kelly McCarthy and Kristen Maurer have shared so much of their lives so when one was once recognized with breast most cancers, she urged the other to get examined, too.