In the last 50 years a wealth of information has allowed us to understand the contribution of various regulatory factors that alter mRNA and protein s- thesis to a variety of physiological and pathological conditions. However, such regulation is only one of many factors that contribute to the levels of a given p- tein. One major factor that has been relatively obscure until recently has been the contribution of protein degradation to the regulation of the steady state level of protein expression and protein function. This rapidly evolving field has made a significant mark on the scientific...