Abstract
Protein regulation is the function of several pathways and enzyme systems in the human body. One of these pathways is the ubiquitin/SUMO pathway. The author has noted that almost all known syndromes of radial ray deficiency are related to this pathway. In this article, these syndromes are reviewed with special attention to their relationship with the ubiquitin/SUMO pathway. This opens a new insight into the pathogenesis of radial ray deficiency syndromes.