AltSplice and AltExtron provide information on alternative intron/exons, alternative splice events, and isoform splice patterns. AEdb contains: AEdb-Sequence (sequence and properties of alternatively splice exons), AEdb-Function (data on functional aspects of alternative splicing), AEdb-motif (data and sequence of known splice regulatory motifs), and AEdb-minigene (a collection of known minigene constructs for alternative splice events).