DPYSL5 and cerebellar ataxia: Improvement in neurologic symptoms following cyclophosphamide as second-line therapy has been observed in ICI-mediated PNSs with a classic paraneoplastic association, including anti-Hu and anti-CRMP5 antibody-positive cerebellar ataxia with peripheral neuropathy and encephalomyelitis, anti-Hu and striational antibody-positive limbic encephalitis with cerebellar ataxia and cranial neuropathy, and anti-CRMP5-positive progressive myelopathy [12, 118].