Surprisingly, T47D cells, which exhibit the highest Orai1:Orai2 expression ratio among the breast cancer cells investigated, were mostly unable to respond with Ca2+ oscillations in response to low and high CCh concentrations (Figure 3l), and Orai2 knockdown was unable to modify significantly the pattern of response to CCh (Figure 3l,m). This evidence concerns the gene ORAI2 and breast carcinoma.