PAX8 and nonpapillary renal cell carcinoma: ,9 The widespread and uniform expression of PAX8,10 a well-established example of a lineage-specific transcription factor dependency,1,2,11,12,13,14 make PAX8 an attractive alternative target for ccRCC therapy, especially given the redundancy between Pax8 and Pax2 in normal renal development in mice.12