PTGS2 and breast cancer: This regulation could extend to other pro-tumorigenic/pro-angiogenic genes that are regulated by α3β1, including fibulin-2 and MRP3 in MK cells [28, 39], and COX-2 in breast cancer cells [48], as these genes harbor potential APA sites that in some cases flank canonical AREs within the 3’-UTR [65, 77].