NO activation of Ets-1 resulted in the cellular expression of basal-like markers (P-cadherin, S100A8, IL-8 and αβ-crystallin) [46-48] as well as molecules associated with the metastatic process (CTSB and MMP-7) [49,50] indicating that this signaling mechanism contributes to the observed clinical features of aggressive ER- breast cancers that overexpress NOS2. Here, CTSB is linked to breast cancer.