In this study, CTP-SOD fusion gene was amplified from human cDNA by PCR, and the active recombinant protein was successfully expressed in Pichia pastoris.     ///    [Expression and purification of fusion protein CTP-SOD in Pichia pastoris and antioxidant capacity analysis]..     ///    "HeLa cells pretreated with CTP-SOD showed a significantly improved survival against the pyrogallol-induced oxidative stress, suggesting CTP-SOD could cross the cell membrane more efficiently and protect cells from oxidative stress.. "