PBRM1 and nonpapillary renal cell carcinoma: Despite the fact that HIF/STAT signaling overdrive was evident in the twelve week-old Vhl-/-;Pbrm1-/- mouse kidney, the long latency (ten months) and the incomplete penetrance (~50%) to the ultimate development of multifocal ccRCC in this model suggested that additional OG-TSG CBs could be at play [42].