QSOX2, also known as Quiescin Sulfhydryl Oxidase 2, is an enzyme involved in the oxidative folding of proteins, particularly those containing multiple disulfide bonds. Positioned predominantly within the endoplasmic reticulum (ER) of cells, QSOX2 plays a crucial role in maintaining protein structure and function by catalyzing the formation of disulfide bonds between cysteine residues. One of the primary functions of QSOX2 is its involvement in protein disulfide bond formation, a process essential for the proper folding, stability, and secretion of secretory and membrane proteins. QSOX2 acts as a thiol oxidase, transferring electrons from reduced cysteine residues to molecular oxygen, thereby facilitating...