Dissimilar immunosuppressive treatments have been used for Hu-PNS, including steroids, intravenous immunoglobulin, immunosuppressants (cyclophosphamide and rituximab) and plasma exchange.[37] Patients with onconeural antibodies against surface or synaptic antigens are more likely to have a marked improvement compared to patients with antibodies against intracellular antigens.[32] Currently, some clinical trials have used programmed cell death protein 1 inhibitors to treat Hu-PNS, but the results are disappointing. Here, PDCD1 is linked to paraneoplastic neurologic syndrome.