Table 1. Observed chimeric partner interactions.

	IG	GENE				TOTAL
IG	162	1402				1564
GENE	1402	4050				5452
A. IG and GENE interactions, 5614 in total.
	IG	EXON			INTRON	TOTAL
IG	162	474			225	861
EXON	474	775			324	1573
INTRON	225	324			68	617
B. IG, EXON and INTRON interactions, 2028 in total.
	IG	CDS	5′UTR	3′UTR	INTRON	TOTAL
IG	162	223	33	185	225	828
CDS	223	195	80	238	181	917
5′UTR	33	80	13	35	27	188
3′UTR	185	238	35	117	94	669
INTRON	225	181	27	94	68	595

C. IG, CDS, 5′UTR, 3′UTR and INTRON interactions, 1876 in total.

Chimeric fusions have been classified as interactions between sequence classes 5′UTR, 3′UTR, EXON, GENE, IG, and INTRON. For instance, in subtable C, there are 33 IG - 5′UTR interactions, meaning that there are 33 chimeric ESTs with an interaction between an intergenic region and a gene; furthermore, the fusion point is located in the 5′UTR region of the gene partner. The GENE class corresponds to cases where no UTR or CDS information exists for the Ensembl gene in question, or the gene had several transcripts that prevented unabmiguous classification of the fusion point. The TOTAL column indicates the total number of times a given class participates in an interaction.