In recent years, research into the SMases has taken large steps forward with the identification and cloning of the various mammalian N-SMases and the elucidation of their cellular localizations, tissue distributions, and biochemical properties. Consequently, considerable progress has begun to be made regarding the functional roles of the nSMases, particularly nSMase2, in regulating signal transduction and a variety of cell processes. However, although many studies have begun to address the important roles of N-SMases in physiological processes, there remain a large number of unanswered questions pertaining to both the regulation and roles of the various cloned nSMase proteins.
