Description of Securities

Exhibit 4.1

DESCRIPTION OF REGISTRANT’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934

The following description of our common stock, par value $0.0001 per share (the “Common Stock”), sets forth the general terms and provisions of our Common Stock. The following summary of our Certificate of Incorporation, as amended (the “Certificate”), and Bylaws (the “Bylaws”) does not describe the Certificate and Bylaws in their entirely. We urge you to read our Certificate and Bylaws, which are filed as exhibits to our Annual Report on Form 10-K, to which this exhibit is also appended.

Authorized Capital Stock. We have authorized 100,000,000 shares of Common Stock and 8,000,000 shares of preferred stock, par value 0.0001 per share (the “Preferred Stock”), which such Preferred Stock may be issued in one or more series with different rights, preferences and privileges. We have authorized 11,000 shares of Series C-1² Convertible Preferred Stock and 10,000 shares of Series F Convertible Preferred Stock.

Voting Rights. Holders of our Common Stock are entitled to one vote per share on all matters to be voted upon by our shareholders. Our Certificate does not provide for cumulative voting in the election of directors. The vote of the holders of a majority of the stock present and entitled to vote at a meeting at which a quorum is present is generally required to take shareholder action, unless a greater vote is required by law or specifically required by our Certificate or Bylaws. Special shareholder meetings may be called by the Chairman of the Board of Directors, the President, the Board of Directors pursuant to a resolution adopted by a majority of the total number of directors we would have if there were no vacancies, or the holders of 10% or more of outstanding shares of our Common Stock. Any shareholder action may, subject to procedural and informational requirements included in our Certificate, be taken by written consent signed by the holders of outstanding shares having no less than the minimum number of votes that would be necessary to authorize or take that action at a meeting at which all shares entitled to vote on that action were present and voted. In addition, our Bylaws include an advance notice procedure with regard to the nomination of candidates for election as directors, other than by or at the direction of the Board of Directors, and with regard to matters to be brought before an annual meeting or special meeting of shareholders. .

Dividends and Other Rights. Holders of our Common Stock are entitled to receive, when and if declared by the Board of Directors from time to time, such dividends and other distributions in cash, stock or property from our assets or funds legally available for such purposes, subject to any dividend preferences that may be attributable to Preferred Stock that may be authorized. In the event of our liquidation, dissolution or winding up, after all liabilities and the holders of each series of Preferred Stock, if any, have been paid in full, the holders of our Common Stock are entitled to share ratably in all remaining assets available for distribution. Our Common Stock has no preemptive, subscription, redemption or conversion rights. There are no sinking fund provisions applicable to our Common Stock.

Board of Directors. The Board of Directors is not classified. At each annual meeting, the successors to the directors whose term expire at that meeting are elected for a term of office to expire at the next annual meeting after their election or until their successors have been duly elected and qualified. Directors may be removed with or without “cause” by a shareholder vote. Vacancies may be filled by the Board of Directors or by the shareholders, provided that only shareholders may fill vacancies created by the removal of a director.

Delaware General Corporation Law Section 203

As a Delaware corporation, we are also subject to the anti-takeover provisions of Section 203 of the Delaware General Corporation Law, which prohibits a Delaware corporation from engaging in a business combination specified in the statute with an interested shareholder (as defined in the statute) for a period

of three years after the date of the transaction in which the person first becomes an interested shareholder, unless certain conditions are satisfied, such as, in advance of the transaction that resulted in the person exceeding 15% ownership, Board approval of such transaction or the business combination or, following the time of such transaction, approval of the business combination by the Board and two-thirds of the outstanding voting stock, excluding the interested shareholder, voting at an annual or special meeting of shareholders.

Exclusive Forum Selection Clause

Our Certificate provides that unless we select or consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware will be the exclusive forum for any claim, including a claim in the right of the Company: (i) that is based on an actual or alleged violation of a duty by a current or former director, officer, employee or shareholder in such capacity; or (ii) as to which the Delaware General Corporation Law confers jurisdiction upon the Court of Chancery. In addition, our Certificate provides that the federal district courts of the United States will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act of 1933 but the forum selection provisions will not apply to claims brought to enforce a duty or liability created by the Securities Exchange Act of 1934.

Transfer Agent. American Stock Transfer & Trust Company, LLC is the Transfer Agent and Registrar for our Common Stock.