By using the "borrowing belly to nurture pearls" technology, cultivating Pinctada maxima pearls on Pinctada fucata can increase the yield of high−quality pearls. However, this heterologous transplantation is prone to causing immune−related mortality. To overcome this technical flaw, researchers are striving to explore the potential mechanisms of immune responses after allograft and xenograft in pearl oysters through proteomic. Through LC−MS/MS analysis, more than 2000 proteins were successfully identified in the serum of Pinctada fucata after transplantation surgery.