COL6A1 and breast angiosarcoma: There was a significant down-regulated expression of COL6A1 (p = 0.0009), COL6A2 (p = 0.02), COL6A3 (p = 0.024), and COL1A1 (p = 0.0015) in liver BA patients compared to controls with the fold change of 12.53-, 5.58-, 21.35-, and 8.41-times, respectively (Additional file 1: Fig. S1; Table 2).