Fourteen cases of CHL and 132 cases of the control group were studied by 10‐color flow cytometry, with markers including CD3, CD4, CD7, CD8, and CD26, as well as calculated parameters such as the CD4:CD8 ratio, percent CD3+CD4+CD26− T‐cells of CD3+CD4+ T‐cells, percent CD3+CD4+CD26− T‐cells of total events, CD7 coefficient of variation among CD3+CD4+CD26− T‐cells, and CD7 median fluorescence intensity of CD3+CD4+CD26− T‐cells relative to CD3+CD8+ T‐cells. This evidence concerns the gene DPP4 and classic Hodgkin lymphoma.