L1 exonization scenarios (I-V) involving sequences belonging to active L1 subfamilies A, TF, GF and related inactivated F subfamily, as identified in this study. The scenarios I-V are supported by 16, 26, 14, 6, and 2 exonization events, respectively (see Fig. 3 for details of cDNA sequences). SA: splice acceptor, SD: splice donor. In blue: L1-derived exons; in purple and gray: exons of transcriptional units; in light purple and light gray: exons which are not included in transcript due to L1 insertion.