CXCR5 and peeling skin syndrome: Among the CD4+CXCR5+PD1+ TFH cells, TFH2 cells were the main increased subset in patients with IgG4-RD compared to HC and pSS patients for both number and percentages (8.5 ± 1.6 cells/μl versus 2.2 ± 0.2 and 2.2 ± 0.4 cells/μl; p < 0.0001 and p = 0.0004, respectively; and 44.2 ± 2.7% versus 33.2 ± 1.6 and 35 ± 2.6%; p = 0.0003 and p = 0.005, respectively).