Item 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE

The information required by this Item pursuant to Item 404 of Regulation S-K is incorporated by reference to the information under the caption "Certain Transactions" contained in our proxy statement for our 2019 annual meeting of stockholders.

The information required by this Item pursuant to Item 407(a) of Regulation S-K regarding the independence of our directors is incorporated by reference to the information under the caption "Meetings of the Board of Directors" contained in our proxy statement for our 2019 annual meeting of stockholders.