SMPD1 and hyperhomocysteinemia: Boini and colleagues first assessed levels of homocysteine in wild-type mice and in mice where ASMase expression was either silenced by a short hairpin RNA (shRNA) or knocked out (ASMase−/−.) No difference was observed in the plasma levels of homocysteine in both models thus affirming that ASMase does not play a role in the pathophysiology of hyperhomocysteinemia.