Fig. 1.

a Gene expression for CD24 is higher in juvenile chondrocytes (J1–J4: donor ages 24 weeks, 6 years, 6 months and 18 months) as compared to adult chondrocytes (A1 − A4; donor age 18 (male), 35 (male), 27 (female) and 39 (female) years); *p < 0.01. b Flow cytometry analyses (right) show a higher percentage of CD24-positive cells in juvenile chondrocyte populations (J1, J2), 92% and 81%, respectively, as compared to 30% and 34% in adult chondrocytes (A1, A2). c CD24 expression is gradually increased during chondrocyte differentiation from human induced pluripotent stem cells (iPSCs). d Human induced pluripotent stem cell-derived chondrocytes (hiChondrocytes) (hiC1–hiC5) expresses CD24 to a greater extent than adult chondrocytes. Gene expression is relative to adult articular chondrocytes (AC)1 in the absence of IL-1ß for each respective gene; *p < 0.01