YY1 and cancer: Immunotherapy has become a mainstay of cancer treatment in many malignancies, and clinical evaluation confirmed that the expression of the oncogene YY1 was upregulated in PD-1+ T cells infiltrating lymphocytes in tumors, suggesting that YY1 may hinder T-cell-mediated tumor immunotherapy, especially since the effect on PD-1/PD-L1 is not fully blocked.