Dr Guerra presents how a protease inhibitor protects a serine protease that is linked to ovarian cancer progression plus how protease inhibitor polymerization overloads the Endoplasmic Reticulum Associated Degradation pathway and Unfolded Protein Response to induce autophagy-linked Hepatocellular Carcinoma. Finally, a mechanistic step-wise summary of the serine protease catalytic triad is presented. Published 03 July 2020.