The differential NTN4 mRNA expression patterns between tumorous and adjacent tissues were summarized in Fig. 1A. NTN4 mRNA expression was significantly lower in invasive breast carcinoma (BRCA), as well as in basal, human epidermal growth factor receptor 2 (Her2+), and luminal breast cancer subtypes, compared with adjacent tissues. The gene discussed is ERBB2; the disease is breast cancer.