Although IL-37 is protective during the development of breast cancer, there is no significant difference in IL-37 mRNA expression of patients with metastasis among ER+/PR+/HER2+, ER+/PR+ and PR+ patients, indicating that IL-37 expression may be stage-dependent, i.e. is more protective for breast cancer patients without metastasis (126). The gene discussed is ERBB2; the disease is breast carcinoma.