Downregulation of PG by COX-2 inhibition ameliorates HSPC/myeloid expansions and reduces expression of NR4A and expression of Treg genes (Foxp3 and CTLA-4) in AML MSCs cocultured with CD34+ populations, indicating an association between the COX2-PG secretome and NR4A-Treg signaling [85]. Here, PTGS2 is linked to acute myeloid leukemia.