Dr. Seidah started studying the processing of precursor proteins at the Clinical Research Institute of Montreal (IRCM) in 1974 and, shortly thereafter, co-discovered ß-endorphin and largely contributed to the biochemical characterization of proopiomelanocortin (POMC, the ß-endorphin precursor), discovered and cloned seven (PC1, PC2, PC4, PC5, PC7, SKI-1 and PCSK9) of the nine known enzymes belonging to the proprotein convertase family.