DPP6 and neoplasm: Among the five genes in ccRCC, ATP6V0D2, DPP6, PADI1 and PLG were significantly associated with AJCC-stage (p < 0.05); ATP6V0D2, C9orf135, DPP6 and PLG were significantly associated with nodal metastasis (p < 0.05); ATP6V0D2, DPP6 and PLG were significantly associated with tumor grade (p < 0.05).