Within the group of patients with malignancy and PNS the expression of GrB-PBMC was elevated if onconeural antibodies were detected (2610; 2390–3700 pg/mg protein) as compared to patients without antibodies (1680; 970–1880 pg/mg protein, p = 0.035, Mann–Whitney test, Fig. 1c). Here, GZMB is linked to paraneoplastic neurologic syndrome.