SSX1 and neoplasm: To get an insight into the function of SSX in tumor cells, we silenced SSX in the melanoma cell line DFW that expresses SSX1 to SSX5 (Figure 1) using plasmids for both stable and doxycycline conditional expression of shRNA molecules targeting SSX1–9 transcripts (Figure 2A and Figure S2) as described in material and methods.