CaS receptor modulators differentially rescue the G670E loss-of-expression mutant. Whereas overnight treatment with the calcimimetics has minimal effect on the expression of the WT CaS receptor in HEK cells, cinacalcet, NPS-R568, calindol, R,R-calcimimetic B and nor-calcimimetic B rescue the expression of the G670E mutant. AC-265347 and S,R-calcimimetic B, however, do not rescue cell surface expression. Data are mean + SEM from at least four independent experiments.