Fig. 1

Immunohistochemical expression patterns of PD-L1 and pSTAT3 in diffuse large B cell lymphoma. PD-L1 is expressed in both tumor and immune cells (a), only in tumor (b) or only in immune cells (c). PD-L1 is not expressed in either tumor cells or immune cells (d). Tumor cell nuclei are positive for pSTAT3 (e), compared to a pSTAT3-negative case (f) (×400 magnification)