In an effort to understand why PFS would be unfavorable in cetuximab-based therapy-treated HNSCC patients with low circulating IL-1 levels, we assessed NK cell activity identified by CD3-CD56 + CD54+ cells (activated NK cells) and CD3-CD53 + CD107a + (NK cell degranulation) by flow cytometry after co-culture of PBMCs with cetuximab and cetuximab+anakinra-treated SQ20B cells. Here, NCAM1 is linked to head and neck squamous cell carcinoma.