To assess whether a decrease in Ca2+ sensitivity of the channels also contributed to the decrease in KCa3.1 function in HNSCC T cells, we measured KCa3.1 conductance in HNSCC T cells in the presence of incremental intracellular free Ca2+ concentrations (1 μM, 3 μM, and 10 μM). This evidence concerns the gene KCNN4 and head and neck squamous cell carcinoma.