MYC and neoplasm: This monophosphorylated c-myc (T58 only) is recognized by the E3 ubiquitin ligase Fbxw7 and degraded by the 26S proteasome.8,9 Highlighting the importance of this degradation pathway in cancer, many of the signaling proteins implicated in the MYC S62/T58 phosphorylation are often deregulated in tumor cells, resulting in altered c-myc phosphorylation and increased c-myc protein stability.5,7