ANXA1 and myxoma: On the other hand, ANXA1 and ANGPTL4 secreted by myxoma cells may bind to their corresponding receptors on macrophages, such as FRP1 and SDC2, to promote M2-like polarization of macrophages.58,59 These findings suggest that the interactions between myxoma cells and macrophages may sustain the growth of mucinous tumor cells (Fig. 6f).