Our findings indicated significant suppression in cell proliferation of chondrocytes in the femoral heads of MRL/lpr mice, as evidenced by reduced expression of specific proliferation markers PCNA and Ki67, which decreased to 53% and 43% of the levels observed in MRL/MpJ controls, respectively, suggesting that SLE impairs the regenerative capabilities of chondrocytes in the femoral heads (Figure 2A,B). The gene discussed is PCNA; the disease is systemic lupus erythematosus.