N -hydroxy-L-arginine as a novel ethnic specific indicator of estrogen-negative breast cancer.

As a heterogeneous disease, breast cancer can be divided into distinct subtypes. Among the two major subsets of estrogen receptor-negative (ER) and ER-positive (ER) tumors, the ER is a more aggressive subtype, more difficult to treat, has greater ethnic disparity concerns, worse prognosis, and almost twice the risk of mortality. We provide here a fundamental delineation of N -hydroxy-L-arginine as a sensitive and reliable ethnic specific indicator for ER breast cancer early-prognosis (United States provisional patent application number 62232816).