MME and neoplasm: Clinicians may be surprised to learn that that common acute lymphoblastic leukemia antigen (CALLA), an important cell surface marker for diagnosis and prognosis of acute lymphoblastic leukemia4; cluster of differentiation 10 (CD10), the immunohistochemical marker correlating to a higher histologic grade, larger tumor size, metastasis, and survival rate in patients with certain solid tumors5,6; and skin fibroblast elastase, implicated in skin aging and wrinkle formation, are also identical to neprilysin7 (Table 1).