ECM remodeling is a key component of metastasis and is strongly influenced by GH, largely through regulation of MMPs, which digest ECM and promote tumor invasion [24,27,59,147] GH has been shown to upregulate MMP2 and MMP9 in multiple cancers [24,31,32,93], and, in UC, elevated circulating levels of these MMPs are linked to aggressive disease and may serve as biomarkers [148,149,150,151,152]. Here, MMP9 is linked to neoplasm.