MYC and neoplasm: FBXW7 is a tumor-suppressive E3 ubiquitin ligase that targets multiple oncogenic proteins, including c-MYC, for proteasome-dependent degradation.206 FBXW7-185aa shows decreased expression levels in cancer tissues compared to adjacent normal tissues and has tumor-suppressive properties: when overexpressed, it decreases cancer cell proliferation in vitro and in xenograft models.