SIRT1 and osteoarthritis: Moreover, Fgf21, shown to alleviate senescence, apoptosis, and ECM degradation in osteoarthritis via the SIRT1‐mTOR signaling pathway (Lu et al. 2021), was upregulated in the agarose encased cells, together with Fgf1 and 2, markers of human fetal growth plate cartilage, and Fgfr3, a key regulator of chondrogenesis.