PTGS2 and leukemia: In accordance with AKBA, ursolic acid and betulinic acid also trigger reduction of VEGF and COX−2 level in other cell lines, including human leukemia cell line Jurkat, human epithelial cell line HCT116, lung cancer cell lines A549, H3255 and Calu-6, human PCa cell line PC3, human colon cancer cell lines RKO and SW480.