TTN and cholangiocarcinoma: Using the expression of TTN-AS1 in healthy individuals’ blood as a control, the ROC curve of TTN-AS1 in cholangiocarcinoma patients’ blood was plotted, resulting in an AUC of 0.738 with a 95% confidence interval of 0.614–0.863, a sensitivity of 71.88%, and a specificity of 68.75% (Fig. 5G).