PKP1 and neoplasm: TMEM108 and C3orf47 were positively correlated with tumor grade and eight genes, including LAD1, TIF1, FGF11, carbonic anhydrase 12 (CA12), G protein subunit α15 (GNA15), junction plakoglobin (JUP), plakophilin 1 (PKP1) and PPARD, were negatively correlated with the tumor grade of ESCC patients.