MYC and nonpapillary renal cell carcinoma: The functional significance of the MYC/HIF cooperation has also been more firmly established in vivo through generation of a genetically engineered mouse model with kidney-specific Vhl and Cdkn2a deletion and doxycycline-regulatable enforced Myc overexpression, which produces tumors that recapitulate several features of human ccRCC [53].