In the absence of targeted treatment options, neoadjuvant chemotherapy (NACT) is applied widely for triple-negative breast cancer (TNBC). Response to NACT is an important parameter predictive of oncological outcomes (progression-free and overall survival). An approach to the evaluation of predictive markers enabling therapy individualization is the identification of tumor driver genetic mutations. This study was conducted to investigate the role ofSEC62, harbored at 3q26 and identified as a driver of breast cancer pathogenesis, in TNBC. We analyzedSEC62expression in The Cancer Genome Atlas database, and immunohistologically investigatedSEC62expression in pre- and post-NACT tissue samples from 64 patients with TNBC treated at the Department of Gynecology and Obstetrics/Saarland University Hospital/Homburg between January 2010 and December 2018 and compared the effect ofSEC62on tumor cell migration and proliferation in functional assays.SEC62expression dynamics correlated positively with the response to NACT (p≤ 0.01) and oncological outcomes (p≤ 0.01).SEC62expression stimulated tumor cell migration (p≤ 0.01). The study findings indicate thatSEC62is overexpressed in TNBC and serves as a predictive marker for the response to NACT, a prognostic marker for oncological outcomes, and a migration-stimulating oncogene in TNBC.