WT1 expression in WT1-infected 32D clones. (A) Western blot analysis of WT1 protein. V₄, V₅, and V₆ , empty vector-infected-32D clones; W₂ , W₃ , W₄ , W₁₀, and W₁₂, wild-type WT1-infected 32D clones; Z₅ and Z₇, mutant WT1-infected 32D clones. (B) RT-PCR analysis of WT1 transcript. RT-PCR was performed as described previously.9 WT1 PCR products were digested with a restriction enzyme HaeIII and electrophoresed on a 1.5% agarose gel. Lane 1, K562 (a human leukemia cell line); lane 2, digestion of 1; lane 3, mouse kidney cells; lane 4, digestion of 3; lane 5, a WT1-infected 32D clone (W₂); lane 6, digestion of 5; lane 7, an empty vector-infected 32D clone (V₄).