FOXD4L3 is a member of the forkhead box (FOX) transcription factor family, which comprises at least 43 genes involved in developmental and cellular processes 1. As a class 1 FOX protein, FOXD4L3 functions as a DNA-binding transcription factor with RNA polymerase II specificity, regulating gene expression in the nucleus and participating in chr9-based transcriptional regulation and anatomical structure morphogenesis. The gene localizes to chromosome 9.3 and shares structural features characteristic of FOX family members, including a conserved forkhead DNA-binding domain 1. Clinically, FOXD4L3 has emerged as relevant to cancer biology. A recurrent truncating mutation (p.Lys108Ter) in exon 1 of FOXD4L3 was identified in well-differentiated retroperitoneal liposarcoma, showing evidence of interaction with the PAX pathway to promote tumorigenesis 2. Additionally, specific mutations within FOXD4L3 demonstrated elevated frequency in familial lung cancer and sporadic lung cancer samples compared to healthy populations, suggesting potential involvement in lung cancer genetic susceptibility 3. These findings indicate FOXD4L3 dysregulation may contribute to malignant transformation, though comprehensive functional characterization remains limited in current literature.