SPAG1 and acute myeloid leukemia: Since a significant relationship was observed between SPAG1 expression and some common prognostic factors such as WBC, cytogenetics and gene mutations, we performed multivariate analysis by Cox regression to confirm the effect of SPAG1 expression on survival rate and demonstrated that SPAG1 expression acted as a positive independent risk factor affecting OS and LFS in whole-cohort AML (both P < 0.001), non-M3 AML (P = 0.003 and 0.005, respectively), or CN-AML patients (P = 0.001 and 0.007, respectively) (Table 3 and Additional file 1: Table S3).