NOD1 and head and neck squamous cell carcinoma: Increased expression level of NOD1 in tumor biopsies, Detroit‐562 and FaDu cell line. Stimulation of NOD1 in HNSCC cells by iE‐DAP increases the production of β‐defensin 2, GM‐CSF, G‐CSF, and upregulates ICAM‐1. NOD1 activation by iE‐DAP increases the apoptosis and decreases the number of dead Detroit‐562 cells.