The dysregulation of expression and activity of MMPs have been implicated in the progression and metastasis of melanoma [82]; indeed, melanoma cells and tumor-associated stromal cells produce and secrete MMP-2, MMP-9, MMP-1, and MMP-3, contributing to ECM remodeling and tumor progression and various factors, including growth factors, cytokines, and hypoxia, can stimulate MMP expression and activity in melanoma cells through signaling pathways such as MAPK/ERK, PI3K/Akt, and NF-κB [83]. The gene discussed is MMP9; the disease is melanoma.