Validation of top gene hits in ESCC patients. A. qRT-PCR analysis of the mRNA expression of CDKN1A, TSPAN4, ELAVL2, JUNB and PAAF1 in ESCC tumor tissues. B. Western blot of the protein expression of CDKN1A, TSPAN4, ELAVL2, JUNB and PAAF1 in ESCC tumor tissues. C. Correlation analysis of mRNA and protein levels of CDKN1A and ELAVL2 in ESCC tumor tissues. *P<0.05, **P<0.01.