Triple-negative breast cancer (TNBC) is defined by the lack of estrogen receptor (ER), progesterone receptor, and amplified human epidermal growth factor receptor expression. TNBC accounts for ∼15% of all breast cancer cases but represents >50% of breast cancer (BC)-related mortalities.1 There is an urgent need for biomarkers that can predict the metastatic potential of TNBC and be used as prognostic indicators or targets for treatment. Transmembrane protein family 132E (TMEM132E, T132E) belongs to the TMEM132 family which encodes single-pass type I transmembrane proteins and consists of TMEM132A, B, C, D, and E.2 The TMEM132 genes have been implicated in various cancers. Single nucleotide polymorphism association analysis suggests that T132E may increase the risk of BC in women undergoing menopausal hormone therapy.3 Few studies have explored the role of TMEM132E in BC, particularly TNBC.