The author’s first paper detailed HMB effect on maintaining protein synthesis even after administration of lipopolysaccharide, TNF-α and angiotensin II.  This second set of experiments in cultured muscle cells showed that HMB attenuated a specific pathway involving caspase 3 and 8, PKR (RNA dependent protein kinase), and reactive oxygen species (ROS) known to activate the ubiquitin-protease pathway.  These data provide evidence as to why HMB is effective in maintaining and building muscle mass in a wide range of conditions such as AIDS, cachexia and aging.