TNFRSF1B and breast angiosarcoma: Significant differences in the expression of TNFR2 were observed in the patients with severe BA compared with healthy volunteers: 75.45% in healthy volunteers, 30.62% in patients with mild BA (p = 0.038), 29.29% in patients with moderate BA (p = 0.051), and 54.5% in patients with severe BA (p = 0.042).