FOXD1 and head and neck squamous cell carcinoma: Gene set enrichment analysis showed that bladder cancer, cell cycle, DNA replication, glycosaminoglycan biosynthesis chondroitin sulfate, homologous recombination, glycan biosynthesis, nucleotide excision repair, p53 signaling pathway, pyrimidine metabolism, and spliceosome may be key pathways regulated by FOXD1 in HNSCC.