In intrahepatic cholangiocarcinoma, lactylation modification of nucleolar proteins (detected by LC-MS/MS or specific antibody Western blot) is a promising early diagnostic marker; this modification regulates the expression of the downstream MADD gene, and specific splice variants of MADD (assessed by qPCR or ELISA) are expected to be used for evaluating tumor malignancy and metastatic potential, serving as independent prognostic indicators. Here, MADD is linked to intrahepatic cholangiocarcinoma.