SOX2 and myxoid liposarcoma: Using the whole set of soft tissue sarcomas, we found a significant inverse correlation of SIX1 with MYL9 and FBLN2, two of the mesenchymal genes most significantly downregulated in the mouse SIX1-expressing tumors, and a tendency to positive correlation with SOX2. Interestingly, the subset of myxoid liposarcomas, characterized by highly frequent SIX1 overexpression (95% of tumors), also showed strong inverse correlation between SIX1 and the mesenchymal markers MYL9 and FBLN2, although no clear correlation with SOX2 was observed in this case (Supplementary Fig. S8).