BMP

BMPs are TGF-β superfamily signaling proteins first defined by bone-inducing activity and now linked to embryogenesis, organ development, and adult tissue homeostasis^[1][2]. Mechanistically, BMP ligands activate type I/type II receptor complexes that phosphorylate SMAD1/5/8, driving context-dependent transcriptional programs^[3]. In limb models, BMP2, BMP4, and BMP7 participate in limb patterning and skeletogenesis, providing a practical developmental framework for BMP pathway research^[4]. Compared with related isoforms, BMP7 functions predominantly as a heterodimer with BMP2 or BMP4 during mammalian embryogenesis, while BMP6 and BMP9 show robust orthotopic bone-forming activity in adenoviral mouse models^[5][6]. For experimental applications, dorsomorphin inhibits BMP type I receptors ALK2, ALK3, and ALK6, whereas LDN-193189 reduces heterotopic ossification by inhibiting BMP type I receptor activity^[7][8].