In a recent study, the association between perineural invasion (PNI) and locoregional recurrence (LRR) accounting for age, tumor size, nodal involvement, estrogen receptor, progesterone receptor, HER2 status, histologic tumor grade, presence of lymphovascular invasion (LVI), and receipt of chemotherapy and/or radiation among a broadly representative cohort of breast cancer patients was evaluated [72]. The gene discussed is ESR1; the disease is neoplasm.