MTOR and breast cancer: Furthermore, previous studies have confirmed that HOXD8 is expressed at low levels in TNBC tissues and cells, and that HOXD8 overexpression could block the phosphorylation of AKT with mammalian target of rapamycin in triple-negative BC cells, suggesting that HOXD8 regulates the malignant behaviors of BC cells by blocking PA-P (Zhang et al., 2021).