CASP6 and neoplasm: Fourteen PRGs were differentially expressed between the BTC and adjacent normal samples; among which, CASP1, CASP6, CASP7, CASP8, FADD, GSDMD, IRF1, MLKL, PARP1, RIPK1, RIPK3, TAB3, TNFAIP3, and TRADD were upregulated in the tumor samples (p < 0.05) (Fig. 1E).