KCNN4 and head and neck squamous cell carcinoma: Indeed, while KCa3.1 peak fluorescence intensities at the membrane were comparable in HD and HNSCC T cells, there was a 37% reduction in membrane KCa3.1-associated CaM (CaM fluorescence intensity corresponding to the KCa3.1 fluorescence intensity peaks, see Materials and Methods) in HNSCC T cells (Figures 3B, C).