PVR and breast carcinoma: In addition, CD155 was highly expressed in tumour cells of multiple cancer types and predicted poor prognosis, such as breast cancer,20 pancreatic cancer,21 cholangiocarcinoma,22 etc. Several researches have been done to explore cell‐extrinsic biology of CD155 acting as an immunomodulatory molecule in tumour progression,6, 23 but little is known about cell‐intrinsic biology of CD155 in HCC cells, including its involvement in cell–cell adhesion, motility and proliferation.4, 5