COL1A1 and disease of the tendon: To investigate the effect of nesfatin-1 on HO in tendinopathy, we detected the expression of osteogenic markers such as COL1A1 (Valles et al., 2020), ALP (Gong et al., 2016), and RUNX2 (Berendsen and Olsen, 2015), under nesfatin-1 stimulation in vitro.