CD4 and cervical cancer: In preclinical studies, they showed that HLA class II-positive tumours recruited the CD4+ T cells and developed dependency on PD-1.44 Further supportive of HLA-DQB1 as an important biomarker for immune activation in cervical cancer, our GSEAs suggest that HLA-DQB1 expression may be a stronger indicator of immune activation than PD-L1.