CD27 and hydrops fetalis: Furthermore, in vitro studies have shown that the interaction between CD27 on B cells and its co-stimulatory ligand CD70 mediates the differentiation of B cells into plasma cells.[35] However, there is a negative correlation between B cell depletion and the formation of atherosclerotic plaques in the body.[36] This implies that CD27 on B cells may increase the risk of coronary artery disease by promoting atherosclerotic immune responses, thereby increasing the potential risk of HF.