The most prevalent ailment in women and the primary reason of mortality globally is breast cancer. Breast cancer membrane protein 11, also known as anterior gradient 3 (AGR3), is excessively expressed in breast cancer and has a crucial function in carcinogenesis. Estrogen, progesterone receptors, and a lower tumor grade are strongly correlated with AGR3 expression in breast cancers. Plasma AGR3 protein concentrations may serve as a diagnostic indicator of early breast cancer. The UALCAN cancer database and Breast Cancer Gene-Expression Miner (bc-GenExMiner) databases were employed to examine the expression of AGR3 in breast cancer and to investigate the relationship between the expression level of AGR3 and clinical markers, including prognostic information in breast cancer. AGR3 expression was elevated in many breast cancer subtypes. According to the KEGG pathway and the Panther pathway, AGR3 is essential for nitrogen metabolism enrichment and glutamine glutamate conversion, respectively. Nitrogen is obtained through nitrogen metabolism, which is used by cancer cells to build nucleotides and proteins. Additionally, also cancer cells rely on the breakdown of glutamine to provide the metabolic intermediates necessary to maintain their bioenergetic and biosynthetic requirements. Next, UALCAN's investigation of the related genes for AGR3 revealed that the genes tetraspanin 13 (TSPAN13) and single-pass membrane protein with coiled-coil domains 4 (SMCO4) have Pearson correlation values of 0.58 and -0.49, respectively. This bioinformatics study suggests that AGR3 may be a biomarker for predicting the outcome of breast cancer. More investigation and clinical trials are necessary to clarify the significance of AGR3 in the treatment of breast cancer.