PTGS2 and breast cancer: Similarly to Institut Curie BC cohort, low COX-2 expression and PIK3CA wild-type status allowed to identify TCGA patients with the worse DFS in the entire cohort (trend, p=0.105, HR: 1.584 (0.9090 to 2.758) and among HR+ tumors (p=0.024, HR: 2.698 [1.142 to 6.376]) (Figure 3C and 3D).