In Fig 6, the subgroup (the retrospective study) demonstrated that the increase of BCR level was potentially relevant to a higher risk of all-cause mortality in patients with HF (HR = 1.59, 95% CI 1.40–1.82; I2 = 49.0%, P = 0.039) as did the subgroup (the prospective study) (HR = 1.69, 95% CI 1.02–2.81; I2 = 93.7%, P = 0.000). This evidence concerns the gene BCR and hydrops fetalis.