We further examined the relationship between levels of mRNA expression in the pyroptosis-related signature and CC grade staging, and found that the expressions of GPX4, GZMA, and GZMB were significantly higher in the G3-4 group compared to the G1-2 group (P < 0.05, Supplementary Figure 4C–4F). Here, GZMB is linked to cholangiocarcinoma.