G2 and S phase‐expressed 1 (GTSE1) was a cell cycle‐related protein encoded by the human gtse1 gene, recent research showed that GTSE1 was associated with cancer cell survival, metastatic behaviour and chemoresistance.15 Besides, GTSE1 study involved a variety of tumours including HCC, gastric cancer and breast cancer, except lung cancer.20, 21. Here, GTSE1 is linked to breast cancer.