SMPD1 and Niemann-Pick disease: Indeed, Testi and co-workers claimed that Epstein-Barr virus (EBV)-transformed lymphoblasts from Niemann-Pick disease (NPD) patients, which have an inherited deficiency in aSMase activity, displayed an impaired Fas-induced apoptosis and failed to produce GD3, whereas aSMase-reconstituted NPD lymphoblasts could accumulate GD3 and undergo efficient Fas-mediated apoptosis [9].