(A) Ben-Men-1 cells carry a deletion of a cytosine residue (del640C; marked with an inverted triangle) in NF2 exon 7, resulting in premature termination. The 17 NF2 exons were obtained from Ben-Men-1 and control DNA by PCR and sequenced according to Materials and Methods. (B) Western blot analysis showed that Ben-Men-1 benign meningioma cells and KT21-MG1 malignant meningioma cells did not express merlin protein, in contrast to normal meningeal cells, IOMM-Lee malignant meningioma cells, HE1-1 embryonic kidney cells, and HMS-97 malignant schwannoma cells. α-tubulin was used as a loading control.