In the control, p16 expression of the pPDGFRαβ+CDH11+ population was significantly higher than that of the other cell types, and p16 expression in the pPDGFRαβ-CDH11+ population was higher than that in the pPDGFRαβ+CDH11– population (pPDGFRαβ+CDH11+ > pPDGFRαβ-CDH11+ > pPDGFRαβ+CDH11–; P < 0.0001 and P < 0.0001, respectively; Supplemental Figure 3); this tendency was the same as that in the RA group (Figure 2B). Here, CDH11 is linked to rheumatoid arthritis.