Based on limited published evidence, FOXD4L6 is a forkhead box transcription factor encoded on chromosome 9 that resulted from a recent human-specific duplication of FOXD4 1. Like other FOX family members, it contains a highly conserved forkhead DNA-binding domain and functions as an RNA polymerase II-specific transcription factor involved in chr9 regulation and transcription control. FOXD4L6 is associated with cell differentiation and anatomical structure morphogenesis through its transcriptional regulatory activity. Recent evidence suggests FOXD4L6 may have clinical significance as a methylation-driven prognostic biomarker in lung squamous cell carcinoma 2, though its precise molecular functions require further investigation.