In addition, STAT3 has been shown to be associated with two important proteolysis pathways, including the ubiquitin-proteasome system (UPS) and apoptosis through activation of caspase-3 (Figure 2), whereas blocking STAT3 preserved muscle mass in a mouse model of C26 colon carcinoma and Lewis lung carcinoma cells [50]. This evidence concerns the gene STAT3 and colon carcinoma.