Except as set forth in Section 23, no waivers of any breach of this Agreement extended by PLx or DPRX to Stockholder shall be construed as a waiver of any rights or remedies of PLx or DPRX, as applicable, with respect to any other stockholder of DPRX who has executed an agreement substantially in the form of this Agreement with respect to Shares held or subsequently held by such stockholder or with respect to any subsequent breach of the Stockholder or any other such stockholder of DPRX.  No waiver of any provisions hereof by any party shall be deemed a waiver of any other provisions hereof by any such party, nor shall any such waiver be deemed a continuing waiver of any provision hereof by such party.