BECN1 and breast neoplasm: In fact, gene deletions BECN1 in breast and ovarian cancers have been shown to be associated with gene deletions BRCA1, suggesting that BECN1 deletions may not be the main cause of breast tumor development and hence the proposed tumor inhibitory function for Beclin1 is controversial183 However, Liang et al. demonstrated decreased proliferation and tumorogenesis of MCF‐7 cells after Beclin1 overexpression.41