CR2 and head and neck squamous cell carcinoma: Moreover, flow cytometry analysis of the peripheral blood mononuclear cells (PBMC), tumor microenvironment, and mucosal area of HNSCC divulges key roles of CD86+/CD21- antigen-presenting B cells and memory B cells with IgD-negative and CD27-positive phenotype in survivance of HPV-related HNSCC patients [68].