In this model, the mRNA level of YAP increased in the ankle of AIA rats on days 6, 8 and 10 after induction (before arthritis onset), followed by an increased expression of its target genes, including E2F transcription factor 1 (E2F1), hexokinase 2 (HK2), ankyrin repeat domain-containing protein 1 (Ankrd1), CTGF and CYR61 on days 10 and 12 after induction (at the arthritis onset; Figure 1B). Here, E2F1 is linked to arthritic joint disease.