TNFRSF1A and breast angiosarcoma: All the patients with BA had lower percentages of double-negative (TNFR1-TNFR2-) cells compared with healthy volunteers; however, no statistically significant difference was found: 57.35% in healthy volunteers, 34.99% in patients with mild BA (p > 0.999), 44.98% in patients with moderate BA (p = 0.768), and 18.58% in patients with severe BA (p = 0.821).