From the perspective of the tumour immune microenvironment, our previous study found that P. gingivalis colonisation in oesophageal cancer cells induces strong expression of the immune checkpoint molecule B7-H4 and lysine demethylation 5B (KDM5B), thereby promoting the evasion or inhibition of the host immune response by tumour cells, with sustained colonisation [51]. The gene discussed is VTCN1; the disease is neoplasm.