NOS2 and triple-negative breast carcinoma: For example, in triple-negative breast cancer cells, increased iNOS level is linked to elevated S-nitrosylation of p21Ras, which promotes oncogenic signaling via mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase 1/2 (ERK)/ETS proto-oncogene 1 (ETS1) [117].