MTOR and breast cancer: Importantly, we found that both protein and mRNA levels of PTEN, the key negative regulator of Akt/mTOR pathway, were decreased in SALL2‐silenced MCF7 cells and upregulated in SALL2‐overexpressing MCF7‐TMR and ZR‐75‐30 cells, compared with control cells (Fig 5B and Appendix Fig S4B), suggesting that PTEN might be a potential downstream target of SALL2 in breast cancer cells.