GSTM1 and head and neck squamous cell carcinoma: Pathway enrichment analysis of DEGs in BAA HNSCC vs. White HNSCC identified the involvement of GSTM1 in the ‘xenobiotic metabolic process’, ‘metabolism of xenobiotics by cytochrome p450’ and ‘drug metabolism-cytochrome p450’ pathways, suggesting that GSTM1 may be important in the treatment response of BAAs with HNSCC.