PDCD1 and hereditary sensory and autonomic neuropathy: CD40LG+ CD4+ T cell subcluster was predominant in the CIP− group, whereas TCF7+ CD4, FOXP3+ Treg, and CXCL13+ CD4 were more frequent in the CIP+ group (Fig. 4D), and the percentage of CIP associated CD4+ T cell subclusters was validated by flow cytometry analysis at the protein level, indicated that GZMB, GZMK, CXCL13, PDCD1(PD1) was highly expressed in CIP+ samples (Fig. 4E).