Recently, Wagenblast et al. [79] showed that the secreted proteins serpin family E member 2 (SERPINE2) and secretory leukocyte peptidase inhibitor (SLPI) are primary regulators of vascular mimicry, and overexpression of SERPINE2 and SLPI is closely related to lung metastasis of breast cancer. The gene discussed is SLPI; the disease is breast carcinoma.