Studies on the biological and clinical relevance of STAG2 mutations have generated conflicting results in different type of malignancies, and the functional consequence of variations in the non-coding sequence of STAG2 in breast cancer remains to be determined.38 Furthermore, the prognostic value of the CROCC-associated signature in ER-negative/HER2-negative breast cancer, including RAD52, HIC1 and TULP3 genes, which have been all associated with TNBC, warrants further investigations.39–42. The gene discussed is STAG2; the disease is breast cancer.