HHLA2 and congenital rubella syndrome: In the training group, high expression of B7-H3, and HHLA2 acted as independent risk factors for unfavorable OS [B7-H3, HR=6.18, 95% CI (2.40 to 15.91), P<0.001; HHLA2, HR=3.67, 95% CI (1.83 to 7.37), P<0.001] and CRS [B7-H3, HR=3.67, 95% CI (1.29 to 10.40), P=0.015; HHLA2, HR=2.64, 95% CI (1.30 to 5.36), P=0.007], and high expression of B7-H4 failed to predict OS [HR=1.34, 95% CI (0.68 to 2.65), P=0.403] and CRS [HR=1.34, 95% CI (0.63 to 2.85), P=0.441].