| On December 18, 2012, Column sold 174,930 Shares pursuant to the New Sales Plan at sale prices that ranged from $16.00 to $16.42 per Share (with a weighted average price of $16.09). On January 7, 2013, Column sold 15,000 Shares pursuant to the New Sales Plan at sale prices that ranged from $17.25 to $17.32 per Share (with a weighted average price of $17.28). On January 8, 2013, Column sold 4,000 Shares pursuant to the New Sales Plan at a sale price of $17.30 per Share. On January 9, 2013, Column sold 17,529 Shares pursuant to the New Sales Plan at sale prices that ranged from $17.25 to $17.30 per Share (with a weighted average price of $17.27). On January 10, 2013, Column sold 9,469 Shares pursuant to the New Sales Plan at sale prices that ranged from $18.00 to $18.50 per Share (with a weighted average price of $18.34). On January 23, 2013, Column sold 41,108 Shares pursuant to the New Sales Plan at sale prices that ranged from $20.60 to $21.05 per Share (with a weighted average price of $20.80). On January 29, 2013, Column sold 47,087 Shares pursuant to the New Sales Plan at sale prices that ranged from $20.98 to $21.35 per Share (with a weighted average price of $21.04). On January 30, 2013, Column sold 62,700 Shares pursuant to the New Sales Plan at sale prices that ranged from $20.93 to $21.05 per Share (with a weighted average price of $20.95). On January 31, 2013, Column sold 88,000 Shares pursuant to the New Sales Plan at sale prices that ranged from $21.00 to $21.39 (with a weighted average price of $21.03). On February 5, 2013, Column sold 22,435 Shares pursuant to the New Sales Plan at sale prices that ranged from $21.28 to $21.49 per Share (with a weighted average price of $21.40). On February 6, 2013, Column sold 14,000 Shares pursuant to the New Sales Plan at sale prices that ranged from $21.36 to $21.69 per Share (with a weighted average price of $21.50). All of the Shares were sold in multiple open market transactions. The Reporting Person undertakes to provide the staff of the SEC, the Company, or a stockholder of the Company, upon request, the number of Shares sold at each separate price within the ranges reported above. |