Additionally, ERBB2-low expression appears to be associated with HR status, with patients with HR-positive invasive BC demonstrating a higher frequency of ERBB2-low tumors than those with HR-negative BC.5,7,9 A recent meta-analysis,10 however, demonstrated an improved OS for patients with ERBB2-low BC in both the early and metastatic settings. This evidence concerns the gene ERBB2 and breast cancer.