HPSE and cancer: In addition, the relative inclusion-to-exclusion ratio of the first exon of heparanase, which was an alternative exon near the siH3-targeted site, did not change after transfection of siH2, siH3, siH4 or siScb in cancer cells (Fig. 2J), suggesting that the regulation of alternative splicing was not involved in siH3-mediated TGS.