Tooth agenesis was also observed in some patients, and Kdf1 was expressed in the epithelium of mandibular processes before the initiation of tooth development and in the dental epithelium at the bud and cap stage (Figure 5A-C), which is consistent with a previous report by Zeng et al.15Some patients had root maldevelopments, and Kdf1 was expressed in Hertwig epithelial root sheath (Figure 5D). The gene discussed is KDF1; the disease is tooth agenesis.