PRTN3 and rheumatoid arthritis: Thus, we sorted single B cells from four fresh (Figure 2) and four frozen (Supplementary Figure 1) gingival tissue biopsies, of PD patients with (n=3) and without (n=4) ACPA+ RA, and retrieved between 108 and 576 live CD3-/CD14-/CD19+ cells from each biopsy.