The opinion of the court was delivered by: Judge Robert M. Dow, Jr.
MEMORANDUM OPINION AND ORDER
Before the Court are Plaintiffs' motion*fn1 and supporting briefs [526 and 533] seeking to bar Defendants from offering any evidence concerning Plaintiffs' alleged misrepresentations or omissions of prior art references to the U.S. Patent and Trademark Office ("PTO") during prosecution of the ancestor applications of the '116 patent, as well as Defendants' response in opposition to the motion  and response to Plaintiffs' reply . Plaintiffs argue in support of their motion that because the Court dismissed four of Defendants' inequitable conduct counterclaims and affirmative defenses  and granted summary judgment for Plaintiffs on another inequitable conduct counterclaim and affirmative defense , any evidence that supported those counterclaims and affirmative defenses cannot now be introduced under Rule 404(b). Plaintiffs further argue that the evidence that Defendants seek to introduce constitutes improper propensity evidence, and thus is barred by Federal Rule of Evidence 404(b). For the reasons set forth below, Plaintiffs' motion  is denied.
I. Summary of the Court's Prior Rulings on Defendants' Inequitable Conduct Counterclaims and Affirmative Defenses "A"-"E"
Defendants alleged in counterclaims and affirmative defenses "A," "B," and "C" that inventor Bishop and Plaintiffs' attorneys Welch and Gulbrandsen engaged in inequitable conduct during prosecution of three ancestor applications of the '116 patent -- the '371, '412, and '056 applications, respectively -- by intentionally misrepresenting and omitting prior art references to the PTO, and that the '116 patent was therefore unenforceable under the doctrine of infectious unenforceability.  The Court determined that although Defendants showed a close relationship between the '116 patent and the ancestor applications, they failed to allege "an immediate and necessary relationship" between the '116 patent and the alleged prior inequitable conduct in the '371, '412, and '056 applications.  Accordingly, the Court concluded that Defendants failed to satisfy the heightened pleading requirements of Federal Rule of Civil Procedure 9(b), and dismissed counterclaims and affirmative defenses "A," "B," and "C." 
Defendants alleged in counterclaim and affirmative defense "E" that Bishop made false and inconsistent statements about prior art references and omitted certain prior art references during prosecution of the '488 application, the continuation-in-part application that eventually issued as the '116 patent.  The Court dismissed counterclaim and affirmative defense "E" after finding that Bishop's characterizations and disclosure of the prior art references were made in good faith. 
In counterclaim and affirmative defense "D," Defendants alleged that during prosecution of the '488 application, Bishop, Welch, and Gulbrandsen intentionally failed to disclose eight prior art references, some of which had been used as bases for rejecting claims in ancestor applications. The Court denied Plaintiffs' motion to dismiss "D" on the ground that Defendants sufficiently alleged non-cumulativeness of the prior art references.  However, the Court granted summary judgment on "D" on the ground that there was no genuine issue of material fact as to whether Plaintiffs had satisfied their duty of candor and good faith in dealings with the PTO by disclosing the eight references in the '488 application's ancestor applications. 
Defendants state that they will attempt to prove at trial their counterclaims and affirmative defenses "F" and "G," which allege that Plaintiffs engaged in inequitable conduct during prosecution of the '488 application, which ultimately issued as the '116 patent.*fn2
Inequitable conduct includes "affirmative misrepresentations of a material fact, failure to disclose material information, or submission of false material information, coupled with an intent to deceive." Molins PLC v. Textron, Inc., 48 F.3d 1172, 1178 (Fed. Cir. 1995) (emphasis added).
In order to prove the "intent" element of inequitable conduct counterclaims and affirmative defenses "F" and "G," Defendants seek to introduce evidence at trial that purports to show that Bishop, Welch, and Gulbrandsen intentionally made material misrepresentations to the PTO concerning prior art references and intentionally omitted prior art references during prosecution of the chain of applications leading up to and including the '488 application. Defendants argue that such evidence is relevant and admissible under Rule 404(b) to show intent, motive, plan, and absence of mistake or accident to deceive the PTO during prosecution of the '488 application.
Rule 404(b) provides that:
Evidence of other crimes, wrongs, or acts is not admissible to prove the character of a person in order to show action in conformity therewith. It may, however, be admissible for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident * * *."
Fed. R. Evid. 404(b). In the Seventh Circuit, a party seeking to offer prior bad acts evidence under Rule 404(b) must satisfy a four-part test: (1) the evidence must aim to establish a matter in issue other than the propensity of the non-asserting party to commit such an act; (2) the evidence must be similar enough and recent enough to be relevant to the matter in issue; (3) the evidence must be substantial enough that a trier of fact could find that the act occurred and that the party against whom the evidence is being offered was the actor; and (4) the probative value of the evidence must not be substantially outweighed by the potential for unfair prejudice to the party against whom the evidence is being offered. Abbott Labs. v. TorPharm, Inc., 2003 WL 22462614, at *27 (N.D. Ill. 2003) (citing United States v. Asher, 178 F.3d 486, 492 (7th Cir. 1999)).
Plaintiffs first argue that Defendants cannot introduce evidence purporting to show alleged misrepresentations and omissions that inventor Bishop and attorneys Welch and Gulbrandsen made to the PTO during prosecution of the '371, '412, '056, and '488 applications because the Court dismissed Defendants' inequitable conduct counterclaims and affirmative defenses "A," "B," "C," and "E" and granted summary judgment on "D," which collectively pertained to those applications.  Plaintiffs submit that Defendants' attempt to introduce evidence of the alleged misrepresentations to the PTO with respect to the four applications seeks to impermissibly revive counterclaims and affirmative defenses "A"-"E" through a Rule 404(b) back door. As Plaintiffs observe, the Court reiterated in a subsequent motion ...