VEGFR-2 levels. Note: The horizontal axis stands for the groups, and the vertical axis stands for VEGFR-2 level. From left to right, the VEGFR-2 level of the four groups respectively is (83.50±9.21) ng/L, (66.35±7.24) ng/L, (65.98±7.54) ng/L, (66.08±7.00) ng/L. a, comparison between the control group and the group A (t=10.35, P<0.001) (P<0.05). b, comparison between the control group and the group B (t=10.41, P<0.001) (P<0.05). c, comparison between the control group and the group C (t=10.65, P<0.001) (P<0.05).