PTPRO and neoplasm: A recent study revealed an increase in IL-6 in patients treated with nivolumab (a PD-1 antibody), and evidence from a mouse model indicated that a combined blockade of both PD1/PD-L1 and IL-6 could significantly increase the therapeutic effects.16 In the present study, we found that a sustained increase in serum IL-6 impaired the anti-inflammatory activity of monocytes, contributed to the potential immunosuppression caused by an increased percentage of PD-L1–producing TAMs within the tumor, and decreased expression of PTPRO within the monocytes.