Common use of Nasdaq Stock Market Clause in Contracts

Nasdaq Stock Market. The Common Stock is registered pursuant to Section 12(g) of the Exchange Act and is quoted on the Nasdaq Stock Market Over-the-Counter Bulletin Board ("OTCBB") under the ticker symbol "PRTX.OB." The Company has taken no action designed to remove, or which, to the Company's knowledge, is likely to have the effect of, suspending or terminating the quotation of the Common Stock on the OTCBB. The Company shall comply with all requirements, if any, of the National Association of Securities Dealers, Inc. (the "NASD") with respect to the issuance of the Shares and Conversion Stock and the quoting of the Shares and Conversion Stock (when issued) on the OTCBB.

Nasdaq Stock Market. The Common Stock is registered pursuant to Section 12(g) of the Exchange Act and is quoted on the Nasdaq Stock Market Over-the-Counter Bulletin Board ("OTCBB") under the ticker symbol "PRTX.OB." The Company has taken no action designed to remove, or which, to the Company's knowledge, is likely to have the effect of, suspending or terminating the quotation of the Common Stock on the OTCBB. The Company shall comply with all requirements, if any, of the National Association of Securities Dealers, Inc. (the "NASD") with respect to the issuance of the Shares and Conversion Stock Warrant Shares and the quoting of the Shares and Conversion Stock Warrant Shares (when issued) on the OTCBB.

Nasdaq Stock Market. The Common Stock is registered pursuant to Section 12(g) of the Exchange Act and is quoted on the Nasdaq Stock Market Over-the-Counter Bulletin Board ("“OTCBB"”) under the ticker symbol "“PRTX.OB." ” The Company has taken no action designed to remove, or which, to the Company's ’s knowledge, is likely to have the effect of, suspending or terminating the quotation of the Common Stock on the OTCBB. The Company shall comply with all requirements, if any, of the National Association of Securities Dealers, Inc. (the "“NASD"”) with respect to the issuance of the Shares and Conversion Stock and the quoting of the Shares and Conversion Stock (when issued) on the OTCBB.

Nasdaq Stock Market. The Common Stock is registered pursuant to Section 12(g) of the Exchange Act and is quoted on the Nasdaq Stock Market Over-the-Counter Bulletin Board ("OTCBB") under the ticker symbol "PRTX.OBSYMBA.OB." The Company has taken no action designed to remove, or which, to the Company's knowledge, is likely to have the effect of, suspending or terminating the quotation of the Common Stock on the OTCBB. The Company shall comply with all requirements, if any, of the National Association of Securities Dealers, Inc. (the "NASD") with respect to the issuance of the Shares and Conversion Stock and the quoting of the Shares and Conversion Stock (when issued) on the OTCBB.

Nasdaq Stock Market. The Common Stock is registered pursuant to Section 12(g) of the Exchange Act and is quoted on the Nasdaq Stock Market Over-the-Counter Bulletin Board ("OTCBB") under the ticker symbol "PRTX.OB." The Company has taken no action designed to remove, or which, to the Company's knowledge, is likely to have the effect of, suspending or terminating the quotation of the Common Stock on the OTCBB. The Company shall comply with all requirements, if any, of the National Association of Securities Dealers, Inc. Financial Industry Regulatory Authority (the "NASD“FINRA") with respect to the issuance of the Shares and Conversion Stock and the quoting of the Shares and Conversion Stock (when issued) on the OTCBB.