Fig. 3A–B.

Identification of splicing variant with exon 8 deletion. Fresh PCR product corresponding to the SS18-SSX1 sequence from all of our cell lines was sent for sequencing analysis. The highlighted portion represents a 93 base pair deletion in the expected coding sequence for SS18-SSX1, which corresponds to the deletion of exon-8 in the SS18 domain of the fusion protein (A). Genomic DNA was isolated from synovial sarcoma cell lines and simplified by PCR with primers designed to flank the exon-8 sequence. Exon-8 was present in the genomic DNA of all three cell lines (B). cDNA from GUSS-3, which lacks the exon-8 sequence, was used as a negative control.