How have courts dealt with the issue of prosecutorial misconduct in criminal cases?

People v. Doolin (2009) 45 Cal.4th 390, 421, fn. 22.) "We presume the jurors treated 'the prosecutor's comments as words spoken by an advocate in an attempt to persuade' [citation]." (People v. Cole (2004) 33 Cal.4th 1158, 1204.) "'A defendant's conviction will not be reversed for prosecutorial misconduct . . . unless it is reasonably probable that a result more favorable to the defendant would have been reached without the misconduct.' [Citation.]" (People v. Harrison (2005) 35 Cal.4th 208, 244.)