Classic Hodgkin lymphoma (CHL) is unique type of B-cell lymphoma [61,62,63,64] in which: (1) the neoplastic Hodgkin and Reed–Sternberg (HRS) cells are rare (less than 1% of the cells in lymph nodes) [64,65], (2) the bulk of the cells in an involved lymph node include reactive lymphocytes, plasma cells, histiocytes and eosinophils [64], and (3) the HRS cells in tissue bind to reactive CD4+ T-cells, resulting in HRS cell-T-cell rosettes [66,67,68,69,70,71,72]. Here, CD4 is linked to classic Hodgkin lymphoma.