MAP3K14 and neoplasm: The matrix-degrading enzyme, MT1-MMP (also known as MMP14), is the predominant proteolytic component of invasive pseudopodia.11, 13, 14 Unlike soluble, secreted MMPs, cell surface localization of active, phosphorylated MT1-MMP (pMT1-MMP, Y573) is required for degradation of ECM proteins and tumor cell invasion.21, 22, 28, 29, 30 We therefore investigated whether NIK promoted pseudopodia formation through regulation of MT1-MMP.