NOD2 and cholangiocarcinoma: In terms of gene expression, we first found that genes AIM2, CASP3, CASP4, CASP5, CASP6, CASP8, GSDMB, GSDMC, GZMB, IL18, NLRP2, NLRP7, NOD2, PYCARD, and TNF were chiefly up-regulated in CC tissues, while the genes ELANE, NLRP1, NOD1, and PJVK were down-regulated.