In summary, the present study showed no significant difference in CD44 expression between cc-RCC and non-ccRCC cases; however, there was significantly higher MMP-2 and MMP-9 expression in non-ccRCC than in ccRCC tumors, which may suggest the presence of different tumorigenic mechanisms between these RCC subtypes. The gene discussed is MMP9; the disease is nonpapillary renal cell carcinoma.