Our ELISA analysis clearly suggests that the relative expression of exo-AnxA2 levels were significantly elevated in TNBC (n = 68, 109.1 ± 2.905 ng/mL) in comparison to ER+ (n = 50, 57.35 ± 1.545 ng/mL, P < 0.0001), HER2+ (n = 59, 78.25 ± 1.146 ng/mL, P < 0.0001), and non-cancer (n = 68, 34.21 ± 2.238 ng/mL, P < 0.0001) serum samples (Fig. 4). This evidence concerns the gene ANXA2 and cancer.