Moreover, the reduction in Dox-induced apoptosis by Ex4a-specific siRNAs was cancelled by concomitant forced overexpression of Ex4a(+)WT1 isoform. These final results indicated that endogenous Ex4a(+)WT1 had a physiological function to advertise apoptosis.DiscussionThe WT1 gene generates four significant isoforms by alternative splicing of exon five (17AA) and exon 9 (KTS). All 4 important isoform