MMP9 and laryngeal carcinoma: MMP‐9 is one example of several proteolytic enzymes that can decrease extracellular matrix and is indispensable for invasiveness, thereby promoting cancerous invasion of nearby tissues.33, 34 It has been shown that MMP‐9 is closely related to lymphatic metastasis and unfavourable prognosis in laryngeal cancer.35 In our current research, the relationship between increased Six1 expression in HCC samples and the elevation MMP‐9 expression was explored.