WT1 and acute myeloid leukemia: We found the ratios for the four major WT1 isoforms to be quite conserved across different cell lines and primary AML blasts with and without WT1 mutations, as the splicing patterns are the result of the WT1 gene structure and mutations in factors of the spliceosome are quite rare and only occur in a monoallelic constellation in the malignant cells analyzed.