Previous studies have indicated that 80% of immune SPS patients are positive for anti-glutamate decarboxylase antibody (GAD-ab), while 11.9% are positive for anti-glycine receptor antibody.[16–18] Another study reported a case of SLS with leukemia and positive anti-glycine receptor antibody.[19] Interestingly, in this case, all tests related to commonly screened antibodies such as serum and cerebrospinal fluid paraneoplastic antibodies, and anti-glycine receptor antibodies were found to be negative.[19] We simultaneously screened for 2 subtypes of GAD antibodies (GAD65 and GAD67). Here, GAD1 is linked to stiff-person syndrome.