PTPRF and macroglossia: Mice lacking both RPTPσ and LAR exhibit mandibular and maxillary bone and cartilage patterning defects, developing micrognathia, cleft palate, and macroglossia.25 The phenotype strongly resembles Pierre Robin Sequence (PRS) in humans.28 Mechanistically, LAR deficiency causes elevated BMP-SMAD signaling and represses canonical Wnt signaling in mouse embryonic tissues.25 These findings suggest that LAR RPTPs function as pivotal regulators of craniofacial morphogenesis, providing insight into the etiology of PRS.