MMP9 and neoplasm: In SH-SY5Y neuroblastoma cells, SPS were able to reduce the proliferation, invasion and metastasis by downregulating the expression of MMP-9, which is one of the major protein hydrolases that can induce the degradation of the extracellular matrix, participating in tumor vasculature and lymphangiogenesis, thereby promoting to tumor invasion and metastasis (Kessenbrock et al., 2010; Qu et al., 2020).