GSN and breast cancer: To determine whether the expression of gelsolin was associated with the BRCA1 mutation status, we examined gelsolin levels in the following panel of BC cell lines: MCF-7 (sporadic breast ductal carcinoma cell line), HCC1937 (a near tetraploid cell line from breast ductal carcinoma, homozygous for a frameshift mutation in BRCA1), and MCF-7shBRCA1 (MCF-7 cells in which BRCA1 has been transiently silenced by Sh-RNA interference).