SPHK1 and gastric cancer: SK1 positivity and high expression were associated with 5-year survival; the HR was 1.86 (95% confidence interval [CI], 1.18–2.94) for breast cancer, 1.58 (1.08–2.31) for gastric cancer, and 2.68 (2.10–3.44) for other cancers; the total cancer HR was 2.21 (95% CI, 1.83–2.67; P < 0.00001).