Abstract: Transmembrane proteins (TMEM) family is widely involved in the structure of the biological membrane, including endoplasmic reticulum, lysosomes and Golgi apparatus. TMEM proteins are reported to play a pivotal role in the development of breast cancer, which have also endowed with dual functions of oncogene and/or suppressor. TMEM is not only involved in regulating the proliferation, invasion and migration of breast cancer cells, but also associated with chemotherapy resistance. Therefore, understandings of the characteristics of the expression, clinical significance and prognostic value of TMEM family members in breast cancer can provide new insights to tumor prevention and treatment.