ERBB2 and breast cancer: In this T > N group, we have presented the HNMT mRNA expression levels of patients with Luminal A, Luminal B, HER2 + , and TNBC BC subtypes, as shown in Fig. 1C. Our analysis revealed that there were no significant differences in HNMT mRNA expression between Luminal A and Luminal B BC patients (P = 0.0949), as well as between Luminal A and HER2 + BC patients (P = 0.1274).