In what circumstances will the Court reject appellant's assertion that expert testimony at trial violated his due process rights and rendered his trial fundamentally unfair?

^7. Likewise, we reject appellant's assertion that the expert testimony violated his due process rights and rendered the trial fundamentally unfair. (See People v. Roybal (1998) 19 Cal. 4th 481, 506, fn. 2 ["The superior court did not abuse its discretion; there is thus no predicate error on which to base the constitutional claims."]; People v. Davis (1995) 10 Cal.4th 481, 506, fn. 2 [no constitutional violation where defendant "recasts his state claim under constitutional labels"].)