SP1 and head and neck squamous cell carcinoma: It is also biologically plausible that the allele G attenuates transcriptional activation mediated by the SP1/STAT1 FAS complex in HNSCC, which in turn dampens the apoptotic pathway of FAS due to its dysregulated expression32,62, favoring the survival of tumor cells, tumor progression or relapse of tumor and death in patients with FAS c.-671GG genotype.