MUC1 interacts with EGFR and activates the EGFR/PI3K/Akt signaling pathway, thereby inducing the aggregation of Foxp3+Treg cells, enhancing the malignant phenotype of cholangiocarcinoma cells, and ultimately promoting the growth and metastasis of cholangiocarcinoma. The gene discussed is FOXP3; the disease is cholangiocarcinoma.