What is the test for a claim of prosecutorial misconduct based on conduct at trial?

2. To succeed on a claim of prosecutorial misconduct based on conduct at trial, a defendant must show that the prosecutor's conduct caused "substantial prejudice" such that the defendant was deprived of a fair trial. United States v. Tocco, 135 F.3d 116, 130 (2d Cir. 1998); see also United States v. Locascio, 6 F.3d 924, 945-46 (2d Cir. 1993). To assess whether substantial prejudice exists, we weigh "the severity of the misconduct, the measures adopted to cure [it], and the certainty of conviction absent the misconduct." United States v. Elias, 285 F.3d 183, 190 (2d Cir. 2002).