We have previously reported the presence of functional CaSR on HET-1A and that downregulation of the CaSR with siRNA (siRNACaSR) transfection inhibited Ca2+-stimulated pERK, IL-8 secretion and intracellular Ca2+ mobilisation in HET-1A cells.12 Ca2+-stimulated BMP-2 production from colonic myofibroblasts21 and Ca2+-stimulated Wnt5a secretion from colon cancer cells25 have all been inhibited by transfection with siRNACaSR. The gene discussed is WNT5A; the disease is colonic neoplasm.