SNAI1 and melanoma: Furthermore, in melanoma cell lines, a PDZ-domain (the postsynaptic density protein (PSD-95), melanoma differentiation associated gene 9 (MDA-9), discs-large tumor suppressor (Dlg), and tight junction protein-1 (ZO-1)) contains a scaffold protein that can silence RKIP transcription by activating SNAIL expression through ERK1/2 and NFκB signaling due to its role in promoting melanoma progression [54,62].