We first examined the series of patient-derived tRCC cell lines, where UOK145 cells expressing SFPQ-TFE3 showed a striking reduction in PAX8 protein expression compared to ccRCC cell lines, but nearly all tRCC cell lines showed some decrease in PAX2 expression compared to the average expression seen in ccRCC lines (Fig. 6G, H). This evidence concerns the gene PAX2 and renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusions.