Mkx, also known as Mohawk homeobox, is a tendon-specific transcription factor. It plays a crucial role in tenogenic differentiation, regulating the development and homeostasis of tendons, periodontal ligaments, and other related tissues. It may be involved in pathways like Hedgehog signaling, Wnt/β-catenin pathway, and is associated with bone remodeling and cell proliferation-differentiation balance. Genetic models, such as gene knockout mice, are valuable tools to study its functions [1,2,3,4].

In gene knockout studies, Mkx-deficient mice exhibit ectopic ossification in the Achilles tendon, indicating Mkx is key for tendon tissue homeostasis and preventing abnormal bone formation in tendons [3]. In orthodontic tooth movement, Mkx-deficient rats showed reduced tooth movement and suppressed osteoclast induction, suggesting Mkx is involved in osteoclastogenesis during mechanical-induced bone remodeling [2]. In periodontal ligament, single-cell RNA sequencing of Mkx-knockout rats revealed Mkx's role in maintaining PDL homeostasis by regulating specific cell populations and gene expression [4].

In conclusion, Mkx is essential for maintaining the homeostasis of tendon and periodontal tissues, playing a significant role in processes like tenogenic differentiation, osteoclast induction, and preventing ectopic ossification. The gene knockout mouse models have provided valuable insights into the role of Mkx in tendon-related and orthodontic-related disease conditions, helping to understand the underlying molecular mechanisms and potentially guiding future therapeutic strategies.