The low signals for GPE and GPC in the echo-sum spectra of the breast are corroborated by an in vitro extract study on breast tumors by Smith et al. (14), where it was shown that GPE and GPC concentrations are low in non-necrotic breast tumors and that, at low field, PDE signals observed in vivo are mainly from phospholipids. This evidence concerns the gene ALDH7A1 and breast neoplasm.