definiens: means any challenge in a legal or administrative proceeding t o the patentability, validity or enforceability of any of the Patent Rights ( or any claim thereof ), including by : ( a ) filing or pursuing a declaratory judgment acti on in which any of the Patent Rights is alleged to be invalid o r unenforceable ; ( b ) citing prior art against any o f the Patent Rights other than in connection with patent prosecu tion, filing a request for or pursuing a re - examina tion of any of the Patent Rights ( other than with COH ’s written agreement ), or becoming a party to or pursuing an interference against any of the Patent Rights ; or ( c ) filing or pursuing any re - examination, oppositio n, cancellation, nullity or other like proceedings aga inst any of the Patent Rights ; but excluding in eac h case ( i ) any challenge raised as a defense against a claim, acti on or proceeding asserted by COH against Licensee, its Affiliates or Sublicensees, ( ii ) actions taken duri ng prosecution of the Patent Rights, and ( iii ) a th ird party naming of Licensee in any legal proceeding against its will, provided that Licensee has taken commerci ally reasonable steps to avoid such participation . In li eu of exercising its rights to terminate under this Section 7.3(a ) COH may elect upon written notice to increase the p ayments due under all of Section 4 by [ * * * ] percent ( [ * * * ] % ), which election will be effective retroact ively to the date of the commencement of the Patent Challenge . Licensee acknowledges and agrees that th is Section 7.3(a ) is reasonable, valid and necessary for the adequate protection of COH ’s interest in and to the Patent Rights, and that would not have granted to Licensee the licenses under those Patent Rights, without thi s Section 7.3(a ) . COH will have the right at any time in its sole discretion to strike this Section 7.3(a ) ( or any portion thereof ) from this Agreement, and COH will have no liability whatsoever as a result of the presence or absence of this Section 7.3(a ) ( or any struck portion thereof )