PTGDR2 and acute promyelocytic leukemia: APL blasts were found to express high levels of surface B7-H6 and prostaglandin D2 (PGD2) that bind to NKp30 and CRTH2 (151) on ILC2s, respectively, to drive potent IL-13 secretion and activation of IL-13R+ myeloid-derived suppressor cells (152).