Post-translational modifications (PTM) by members of the ubiquitin family are at the heart of almost every biological process, including regulation of protein levels, localization, and quality control. Defects in this protein homeostasis (proteostasis) can result in developmental anomalies and disease. An intricate interplay exists among the ubiquitin-family members, with diverse chains and linkages that constitutes a “ubiquitin code”, the full meaning of which is largely unknown. Fundamental research on the ubiquitin code continues to grow, with the pharmaceutical industry taking…