Notably, the OVCAR5 cell lines used in this study exhibit no ErbB3 signaling, and the TOV21G and lgrov-1 cells express low levels of ErbB3 protein, suggesting that the expression of erbB3 and Gab2 contribute to activation of the PI3K pathway in different subsets of ovarian cancer (50). This evidence concerns the gene GAB2 and ovarian cancer.