Taken together, the possible interaction of septin-9 with F-actin and microtubules, combined with the altered expression of β-actin and β-tubulin, Cdc42, Rac, RhoA in SEPT9 engineered cells lends insight into mechanisms by which SEPT9_i1 may contribute to organization of cytoskeleton in breast cancer cells. This evidence concerns the gene CDC42 and breast cancer.