Our data show an association between the expression of KCa1.1 channels formed of α and β3 subunits, high current densities, and a high expression of CD44, previously shown in RA synovial tissues [49, 50], whereas the αβ1 phenotype was associated with low expression of CD44 and lower current densities. This evidence concerns the gene KCNMA1 and rheumatoid arthritis.