The plaza, near the financial district ground zero, is open to the public but privately owned.___ Geron's exit a symbolic ding for stem cell research WASHINGTON (AP) â¿¿ Geron Corp. is exiting the field it pioneered in a calculated business move that underscores the long, costly path embryonic stem cells face to become real-world products. Late Monday, the company said it would halt its study of a stem cell-based treatment for spinal cord injury, the first embryonic stem cell trial approved in the U.S. Geron's withdrawal leaves a handful of U.S. companies pursuing medicines using embryonic stem cells, which are capable of morphing into any of the more than 220 cell types in the human body. Scientists hope that one day stem cells might be used to replace or repair damaged tissue from ailments such as heart disease, Parkinson's and stroke. The Menlo, Park-Calif., company had long been viewed as the undisputed leader in stem cell therapies, thanks to patents on technology used to grow, manipulate and inject stem cells into the human body. The company helped finance researchers at the University of Wisconsin who first isolated human embryonic stem cells in 1998, allowing the cells to be grown in the laboratory. ___ Deficit hits record $26 billion for US pension insurer WASHINGTON (AP) â¿¿ The federal agency that insures pensions for one in seven Americans ran the largest deficit last year in its 37-year history. The Pension Benefit Guaranty Corp. says it ran a $26 billion imbalance for the budget year that ended Sept. 30. The agency has been battered by the weak economy, which has brought more bankruptcies and failed pension plans. Its pension obligations rose by $4.5 billion. The PBGC also earned less money in the stock market, which helps to fund pension plans. Returns were $3.6 billion, half what it earned the previous year.