Genes upregulated in SjS included CXCL13, CXCR5, CD22, CD19, IGHG1, IL21, IFNG and SMR3B. Genes upregulated in Sicca included SCGB1D2, CAMP, SCGB2A1, S100A2, and LGALS7B. In SjS, but not in Sicca samples, we identified a distinct CCR6+LTB+BAFF+ T helper cell cluster, a CXCL13+CD40LG+ T cell cluster and several B cell clusters (Fig. 4b and supplementary Fig. 4a, b). The gene discussed is IL21; the disease is Schwartz-Jampel syndrome.