To evaluate the expression level of PGD2 in DLBCL patients, analysis based on ELISA assay showed that compared with healthy control (n = 19), DLBCL patients (n = 53) displayed higher concentration of serum PGD2 (46.32 pg/mL vs 12.24 pg/mL) (Fig. 1A). This evidence concerns the gene HPGDS and diffuse large B-cell lymphoma.