BMI1 and cholangiocarcinoma: T-CD8-positive cells’ chemotaxis is also modulated in CCA, via EV-B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1), which is significantly elevated in the malignant tissue, leading to CCA growth, progression, migration, and metastasis, constituting a possible druggable target [81,128,129].