MAPK3 and nonpapillary renal cell carcinoma: Through the Gene Expression Omnibus (GEO) database, the Cancer Genome Atlas (TCGA) database and immunohistochemical (IHC) staining, we observed that compared with adjacent normal renal tissues, in ccRCC tissues the mRNA and protein levels of MMP9 were enhanced, and the mRNA levels of GTP-binding protein smg p21B(RAP1B), B rapidly accelerated fibrosarcoma (RAF), methyl ethyl ketone2 (MEK2), extracellular regulated protein kinases1 (ERK1), ERK2, v-ets avian erythroblastosis virus E26 oncogene homolog1 (ETS1) and ETS2 also increased.