SERPINE1 and breast cancer: Moreover, uPA‐PAI‐1 did not directly induce neutrophil extracellular trap (NET) formation in neutrophils sequestering circulating tumor cells (Demers etal, 2012; Cedervall etal, 2015), thus indicating that uPA‐PAI‐1 primes neutrophils toward a pro‐tumorigenic phenotype that particularly exerts pro‐proliferative effects on breast cancer cells via the release of NE.