PTGS1 and breast cancer: Specifically, we observed up-regulation of genes that drive breast cancer metastasis (IL13RA2 [41], MMP3 [42], PTGS1 [43], SYK [44], VCAN [45], and FLT1 [46]) and downregulation of metastasis-associated suppressor genes (NOTCH3 [47], and HTRA3 [48]).