Interestingly, a reduced activity of NHE4, but not NHE1 or NHE2 isoforms, without altering its protein expression level, was recently suggested in T84 cells (from human colon carcinoma) in response to Escherichia coli strains‐released heat‐stable enterotoxins 89. The gene discussed is SLC9A2; the disease is colon carcinoma.